+ All Categories
Home > Documents > On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere...

On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere...

Date post: 08-Jun-2020
Category:
Upload: others
View: 4 times
Download: 0 times
Share this document with a friend
158
On exact computation of square ice entropy Silv` ere Gangloff LIP, ENS Lyon March 11, 2019 1 / 32
Transcript
Page 1: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

On exact computation of square ice entropy

Silvere Gangloff

LIP, ENS Lyon

March 11, 2019

1 / 32

Page 2: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

I. Representations of square ice

2 / 32

Page 3: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Square ice model [Pauling-Lieb]:

3 / 32

Page 4: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Wang tiles representation [Six-vertex model]

4 / 32

Page 5: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Wang tiles representation [Six-vertex model]

4 / 32

Page 6: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Wang tiles representation [Six-vertex model]

4 / 32

Page 7: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Wang tiles representation [Six-vertex model]

5 / 32

Page 8: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Wang tiles representation [Six-vertex model]

5 / 32

Page 9: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Discrete curves subshift [X s]:

6 / 32

Page 10: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Discrete curves subshift [X s]:

6 / 32

Page 11: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Example of apparition in symbolic dynamics:

S.Gangloff, M. Sablik, Quantified block gluing, aperiodicity and entropy ofmultidimensional SFT , 2017.

Entropy value ?

E.H. Lieb, Residual entropy of square ice, Physical Review, 1967.

→ Proof under some hypothesis

S. Gangloff, A proof that square ice entropy is 32 log2(4/3), 2019.

7 / 32

Page 12: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Example of apparition in symbolic dynamics:

S.Gangloff, M. Sablik, Quantified block gluing, aperiodicity and entropy ofmultidimensional SFT , 2017.

Entropy value ?

E.H. Lieb, Residual entropy of square ice, Physical Review, 1967.

→ Proof under some hypothesis

S. Gangloff, A proof that square ice entropy is 32 log2(4/3), 2019.

7 / 32

Page 13: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Example of apparition in symbolic dynamics:

S.Gangloff, M. Sablik, Quantified block gluing, aperiodicity and entropy ofmultidimensional SFT , 2017.

Entropy value ?

E.H. Lieb, Residual entropy of square ice, Physical Review, 1967.

→ Proof under some hypothesis

S. Gangloff, A proof that square ice entropy is 32 log2(4/3), 2019.

7 / 32

Page 14: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Example of apparition in symbolic dynamics:

S.Gangloff, M. Sablik, Quantified block gluing, aperiodicity and entropy ofmultidimensional SFT , 2017.

Entropy value ?

E.H. Lieb, Residual entropy of square ice, Physical Review, 1967.

→ Proof under some hypothesis

S. Gangloff, A proof that square ice entropy is 32 log2(4/3), 2019.

7 / 32

Page 15: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

II. Subshifts of finite type and entropy

8 / 32

Page 16: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1 01

1

0

1 oops0

1

1

9 / 32

Page 17: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1 01

1

0

1 oops0

1

1

9 / 32

Page 18: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1 01

1

0

1 oops0

1

1

9 / 32

Page 19: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

1

0

1 01

1

0

1 oops0

1

1

9 / 32

Page 20: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1

01

1

0

1 oops0

1

1

9 / 32

Page 21: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1 01

1

0

1 oops0

1

1

9 / 32

Page 22: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1 01

1

0

1 oops

0

1

1

9 / 32

Page 23: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

SFT (subshift of finite type): subset of AZ2, defined by a finite set of

forbidden patterns.

Ex: Hard square shift, or hard core model.

Forbidden patterns 11

et 1 1 .

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

1

1

10

1 01

1

0

1 oops0

1

1

9 / 32

Page 24: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 25: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 26: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 27: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 28: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 29: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 30: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 31: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 32: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 33: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 34: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 35: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 36: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 37: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 38: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 39: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 40: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 41: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 42: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 43: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 44: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 45: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 46: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 47: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 48: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 49: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 50: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy: ”quantity of possible states of the system”.

NN(X ): number of size N square patterns observable in the system.

Free tiles

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

1 1

0 0

0 1

0 1

0 0

1 1

1 0

1 0

1 1

1 0

1 1

0 1

1 0

1 1

0 1

1 1

1 1

1 1

N2(X ) = 222

NN(X ) = 2N2

Hard core

0 0

0 0

1 0

0 0

0 1

0 0

0 0

1 0

0 0

0 1

1 0

0 1

0 1

1 0

N2(X ) = 7

NN(X ) = 2N2(h(X )+o(1))

10 / 32

Page 51: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of a SFT X:

h(X ) = infN

log2(NN(X ))

N2

= infN

log2(N locN (X ))

N2

Free tiles

h = 1

Hard core

h ≥ 1/2

Square ice [Lieb 67]

h = 32 log2(4/3)

Computable from above:

AlgorithmN = 1h(X )

r1

N = 2h(X )

r2N = 3

h(X )

r3N = 4

h(X )

r4

11 / 32

Page 52: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of a SFT X:

h(X ) = infN

log2(NN(X ))

N2= inf

N

log2(N locN (X ))

N2

Free tiles

h = 1

Hard core

h ≥ 1/2

Square ice [Lieb 67]

h = 32 log2(4/3)

Computable from above:

AlgorithmN = 1h(X )

r1

N = 2h(X )

r2N = 3

h(X )

r3N = 4

h(X )

r4

11 / 32

Page 53: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of a SFT X:

h(X ) = infN

log2(NN(X ))

N2= inf

N

log2(N locN (X ))

N2

Free tiles

h = 1

Hard core

h ≥ 1/2

Square ice [Lieb 67]

h = 32 log2(4/3)

Computable from above:

AlgorithmN = 1h(X )

r1

N = 2h(X )

r2N = 3

h(X )

r3N = 4

h(X )

r4

11 / 32

Page 54: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of a SFT X:

h(X ) = infN

log2(NN(X ))

N2= inf

N

log2(N locN (X ))

N2

Free tiles

h = 1

Hard core

h ≥ 1/2

Square ice [Lieb 67]

h = 32 log2(4/3)

Computable from above:

AlgorithmN = 1h(X )

r1N = 2

h(X )

r2

N = 3h(X )

r3N = 4

h(X )

r4

11 / 32

Page 55: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of a SFT X:

h(X ) = infN

log2(NN(X ))

N2= inf

N

log2(N locN (X ))

N2

Free tiles

h = 1

Hard core

h ≥ 1/2

Square ice [Lieb 67]

h = 32 log2(4/3)

Computable from above:

AlgorithmN = 1h(X )

r1N = 2

h(X )

r2N = 3

h(X )

r3

N = 4h(X )

r4

11 / 32

Page 56: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of a SFT X:

h(X ) = infN

log2(NN(X ))

N2= inf

N

log2(N locN (X ))

N2

Free tiles

h = 1

Hard core

h ≥ 1/2

Square ice [Lieb 67]

h = 32 log2(4/3)

Computable from above:

AlgorithmN = 1h(X )

r1N = 2

h(X )

r2N = 3

h(X )

r3N = 4

h(X )

r4

11 / 32

Page 57: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

II. Lieb transfer matrices approach

12 / 32

Page 58: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Entropy of square ice:

h(X s) = limM,N

log2(NM,N(X s))

MN.

Stripes subshifts:

X s

X sN

h(X s) = limN

h(X sN)

N

13 / 32

Page 59: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Cylindric stripes subshifts:

X sN

XsN

Symmetry properties of square ice imply:

h(X s) = limN

h(XsN)

N

14 / 32

Page 60: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Cylindric stripes subshifts:

X sN

XsN

Symmetry properties of square ice imply:

h(X s) = limN

h(XsN)

N

14 / 32

Page 61: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 62: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 63: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 64: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 65: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 66: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 67: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 68: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 69: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 70: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 71: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 72: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Symmetry properties of square ice:

15 / 32

Page 73: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t)

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 74: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t)

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 75: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t) ≡

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 76: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t) ≡

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 77: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t) ≡

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 78: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t) ≡

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 79: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t) ≡

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 80: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lieb transfer matrices:

VN(t) ≡

R[w ]u

v

w

VN(t)[u, v ] =∑

uR[w ]v

t |w |.

where |w | = # of and

h(X s) = limN

log2(λmax(VN(1)))

N

16 / 32

Page 81: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

LiebT xN(t)

17 / 32

Page 82: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

Lieb

T xN(t)

17 / 32

Page 83: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

Lieb

T xN(t)

17 / 32

Page 84: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

LiebT xN(t)

17 / 32

Page 85: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

LiebT xN(t)

17 / 32

Page 86: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

LiebT xN(t)

17 / 32

Page 87: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Computing maximal eigenvalue of VN(1), strategy:

VN(1)

VN(t)

Yang-Baxter

Analycity

Alg. Bethe ansatz

LiebT xN(t)

17 / 32

Page 88: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

III. Yang-Baxter transfer matrices

18 / 32

Page 89: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices:

→ : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 90: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 91: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 92: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )

R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 93: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )

R(0, 1) =

(0

)

R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 94: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)

R(0, 1) =

(0 λ

)

R(0, 1) =

(0 λ0

)R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 95: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)

R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 96: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)

1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 97: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)

1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 98: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 99: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 100: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 101: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 102: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 103: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0

. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 104: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 105: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 106: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0

. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 107: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0

. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 108: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

R-matrices and monodromy matrices: → : input/output:

1

0

R(0, 1) =

( )R(0, 1) =

(0

)R(0, 1) =

(0 λ

)R(0, 1) =

(0 λ0

)

R(0, 1) =

(0 λ0 0

)1 0

0

0

0

0

1

0

0

1

1

0

. . .

. . .

η ∈ {0, 1}N

ε ∈ {0, 1}N

MN(1, 0)[ε,η]

Yang-Baxter transfer matrices:

TN [ε,η] =∑

u∈{0,1}

MN(u, u)[ε,η].

19 / 32

Page 109: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Composition of these matrices and condition for commutation:

0

1

0

1

1

0

Yang-Baxter equation:

R

R’S =

R’

RS

20 / 32

Page 110: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Composition of these matrices and condition for commutation:

0

1

0

1

1

0

Yang-Baxter equation:

R

R’S =

R’

RS

20 / 32

Page 111: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Trigonometric R-matrices: for t ∈ (0,√

2], 2− t2 = − cos(µt):

Rxµt =

1

sin(µt/2)

sin(µt − x) 0 0 0

0 sin(x) sin(µt) 00 sin(µt) sin(x) 00 0 0 sin(µt − x)

.

Bethe ansatz: if (pj)j is solution of:

Npj = 2πj − (n + 1)π −n∑

k=1

Θt(pj , pk)

then we have a candidate eigenvector for the eigenvalue:

n∏k=1

Lt(eipk ) +

n∏k=1

Mt(eipk ).

→ Known: existence and analycity in t.

21 / 32

Page 112: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Trigonometric R-matrices: for t ∈ (0,√

2], 2− t2 = − cos(µt):

Rxµt =

1

sin(µt/2)

sin(µt − x) 0 0 0

0 sin(x) sin(µt) 00 sin(µt) sin(x) 00 0 0 sin(µt − x)

.

Bethe ansatz: if (pj)j is solution of:

Npj = 2πj − (n + 1)π −n∑

k=1

Θt(pj , pk)

then we have a candidate eigenvector for the eigenvalue:

n∏k=1

Lt(eipk ) +

n∏k=1

Mt(eipk ).

→ Known: existence and analycity in t.

21 / 32

Page 113: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Trigonometric R-matrices: for t ∈ (0,√

2], 2− t2 = − cos(µt):

Rxµt =

1

sin(µt/2)

sin(µt − x) 0 0 0

0 sin(x) sin(µt) 00 sin(µt) sin(x) 00 0 0 sin(µt − x)

.

Bethe ansatz: if (pj)j is solution of:

Npj = 2πj − (n + 1)π −n∑

k=1

Θt(pj , pk)

then we have a candidate eigenvector for the eigenvalue:

n∏k=1

Lt(eipk ) +

n∏k=1

Mt(eipk ).

→ Known: existence and analycity in t.

21 / 32

Page 114: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Trigonometric R-matrices: for t ∈ (0,√

2], 2− t2 = − cos(µt):

Rxµt =

1

sin(µt/2)

sin(µt − x) 0 0 0

0 sin(x) sin(µt) 00 sin(µt) sin(x) 00 0 0 sin(µt − x)

.

Bethe ansatz: if (pj)j is solution of:

Npj = 2πj − (n + 1)π −n∑

k=1

Θt(pj , pk)

then we have a candidate eigenvector for the eigenvalue:

n∏k=1

Lt(eipk ) +

n∏k=1

Mt(eipk ).

→ Known: existence and analycity in t.

21 / 32

Page 115: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Trigonometric R-matrices: for t ∈ (0,√

2], 2− t2 = − cos(µt):

Rxµt =

1

sin(µt/2)

sin(µt − x) 0 0 0

0 sin(x) sin(µt) 00 sin(µt) sin(x) 00 0 0 sin(µt − x)

.

Bethe ansatz: if (pj)j is solution of:

Npj = 2πj − (n + 1)π −n∑

k=1

Θt(pj , pk)

then we have a candidate eigenvector for the eigenvalue:

n∏k=1

Lt(eipk ) +

n∏k=1

Mt(eipk ).

→ Known: existence and analycity in t.21 / 32

Page 116: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Identification to λmax(VN(t)): ingredients:

1 Simplification of equations when t =√

2.

2 For some HN diagonalised, VN(√

2)HN = HNVN(√

2).

3 Perron-Frobenius theorem.

4 Indentification around√

2, on (0,√

2) by analycity.

22 / 32

Page 117: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Identification to λmax(VN(t)): ingredients:

1 Simplification of equations when t =√

2.

2 For some HN diagonalised, VN(√

2)HN = HNVN(√

2).

3 Perron-Frobenius theorem.

4 Indentification around√

2, on (0,√

2) by analycity.

22 / 32

Page 118: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Identification to λmax(VN(t)): ingredients:

1 Simplification of equations when t =√

2.

2 For some HN diagonalised, VN(√

2)HN = HNVN(√

2).

3 Perron-Frobenius theorem.

4 Indentification around√

2, on (0,√

2) by analycity.

22 / 32

Page 119: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Identification to λmax(VN(t)): ingredients:

1 Simplification of equations when t =√

2.

2 For some HN diagonalised, VN(√

2)HN = HNVN(√

2).

3 Perron-Frobenius theorem.

4 Indentification around√

2, on (0,√

2) by analycity.

22 / 32

Page 120: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Identification to λmax(VN(t)): ingredients:

1 Simplification of equations when t =√

2.

2 For some HN diagonalised, VN(√

2)HN = HNVN(√

2).

3 Perron-Frobenius theorem.

4 Indentification around√

2, on (0,√

2) by analycity.

22 / 32

Page 121: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

IV. Asymptotics

23 / 32

Page 122: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Asymptotics of counting functions:

nk/Nk → 1/2. Solution of the

equations for Nk , nk : (p(k))j )j = (κt(α

(k)j ))j .

ξ(k)t : α 7→ 1

2πκt(α) +

nk + 1

2Nk+

1

2πNk

nk∑j=1

θt(α,α(k)j )

j/Nk

α(k)j

limN

log2(λmax(VN(1))

N= lim

k

1

Nk

nk∑j=1

f (α(k)j ) =

∫Rf (α)ρt(α)dα.

24 / 32

Page 123: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Asymptotics of counting functions: nk/Nk → 1/2.

Solution of the

equations for Nk , nk : (p(k))j )j = (κt(α

(k)j ))j .

ξ(k)t : α 7→ 1

2πκt(α) +

nk + 1

2Nk+

1

2πNk

nk∑j=1

θt(α,α(k)j )

j/Nk

α(k)j

limN

log2(λmax(VN(1))

N= lim

k

1

Nk

nk∑j=1

f (α(k)j ) =

∫Rf (α)ρt(α)dα.

24 / 32

Page 124: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Asymptotics of counting functions: nk/Nk → 1/2. Solution of the

equations for Nk , nk : (p(k))j )j = (κt(α

(k)j ))j .

ξ(k)t : α 7→ 1

2πκt(α) +

nk + 1

2Nk+

1

2πNk

nk∑j=1

θt(α,α(k)j )

j/Nk

α(k)j

limN

log2(λmax(VN(1))

N= lim

k

1

Nk

nk∑j=1

f (α(k)j ) =

∫Rf (α)ρt(α)dα.

24 / 32

Page 125: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Asymptotics of counting functions: nk/Nk → 1/2. Solution of the

equations for Nk , nk : (p(k))j )j = (κt(α

(k)j ))j .

ξ(k)t : α 7→ 1

2πκt(α) +

nk + 1

2Nk+

1

2πNk

nk∑j=1

θt(α,α(k)j )

j/Nk

α(k)j

limN

log2(λmax(VN(1))

N= lim

k

1

Nk

nk∑j=1

f (α(k)j ) =

∫Rf (α)ρt(α)dα.

24 / 32

Page 126: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Asymptotics of counting functions: nk/Nk → 1/2. Solution of the

equations for Nk , nk : (p(k))j )j = (κt(α

(k)j ))j .

ξ(k)t : α 7→ 1

2πκt(α) +

nk + 1

2Nk+

1

2πNk

nk∑j=1

θt(α,α(k)j )

j/Nk

α(k)j

limN

log2(λmax(VN(1))

N= lim

k

1

Nk

nk∑j=1

f (α(k)j ) =

∫Rf (α)ρt(α)dα.

24 / 32

Page 127: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Asymptotics of counting functions: nk/Nk → 1/2. Solution of the

equations for Nk , nk : (p(k))j )j = (κt(α

(k)j ))j .

ξ(k)t : α 7→ 1

2πκt(α) +

nk + 1

2Nk+

1

2πNk

nk∑j=1

θt(α,α(k)j )

j/Nk

α(k)j

limN

log2(λmax(VN(1))

N= lim

k

1

Nk

nk∑j=1

f (α(k)j ) =

∫Rf (α)ρt(α)dα.

24 / 32

Page 128: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

RR

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |Kξ

(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 129: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |Kξ

(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 130: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |Kξ

(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 131: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)t

ξ(0)t |Kξ(1)t |Kξ(2)t |Kξ

(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 132: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)t

ξ(0)t |K

ξ(1)t |Kξ(2)t |Kξ

(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 133: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |K

ξ(1)t |K

ξ(2)t |Kξ

(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 134: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |K

ξ(2)t |K

ξ(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 135: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |K

ξ(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 136: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |K

ξ(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 137: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |K

ξ(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 138: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Strategy:

1 Extend ξ(k)t on a stripe including R:

R

R

ξ(k)tξ

(0)t |Kξ(1)t |Kξ(2)t |K

ξ(+∞)t |K

2 Assume (ξt)ν(k) → ξ

(+∞)t on any compact K .

3 ξ(+∞)t verifies an integral equation with unique solution ρt .

4 Thus, ξ(k)t → ξ

(∞)t .

25 / 32

Page 139: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 140: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 141: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 142: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 143: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 144: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 145: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 146: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Rarefaction of the roots and ξ(k)t biholomorphisms: ε > 0:

(∞)t

)′> 0

1Nk

∣∣∣∣j : {α(k)j /∈

(k)t

)−1([−M,M])}

∣∣∣∣ ≤ ε

-M M

Γ

V

The functions have distinct values on V and Γ. Thus they arebihilomorphisms onto V.

26 / 32

Page 147: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lace integral expression of ξ(k)t :

Γ

j/Nk

By residues theorem:

ξ(k)t (α) =

1

2πκt(α) +

nk + 1

2Nk+

∮Γ

θt

((ξ

(k)t

)−1(α)

)e2iπsNk

e2iπsNk − 1ds + O(ε).

27 / 32

Page 148: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Lace integral expression of ξ(k)t :

Γ

j/Nk

By residues theorem:

ξ(k)t (α) =

1

2πκt(α) +

nk + 1

2Nk+

∮Γ

θt

((ξ

(k)t

)−1(α)

)e2iπsNk

e2iπsNk − 1ds + O(ε).

27 / 32

Page 149: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Fredholm integral equation: Limit and change of variable:

ξ(∞)t (α) =

1

2πκt(α) +

1

4+

∫ +∞

0θt(α)

(∞)t

)′(α)dα.

Solution by Fourier transforms.

28 / 32

Page 150: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Fredholm integral equation: Limit and change of variable:

ξ(∞)t (α) =

1

2πκt(α) +

1

4+

∫ +∞

0θt(α)

(∞)t

)′(α)dα.

Solution by Fourier transforms.

28 / 32

Page 151: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Final computation:

h(X s) =

∫R

log2(2| sin(κt(α))/2|).ρt(α)dα.

Through an expression of ρt =(ξ

(∞)t

)′and lace integrals computations:

h(X s) =3

2log2(4/3) .

29 / 32

Page 152: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Final computation:

h(X s) =

∫R

log2(2| sin(κt(α))/2|).ρt(α)dα.

Through an expression of ρt =(ξ

(∞)t

)′and lace integrals computations:

h(X s) =3

2log2(4/3) .

29 / 32

Page 153: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Final computation:

h(X s) =

∫R

log2(2| sin(κt(α))/2|).ρt(α)dα.

Through an expression of ρt =(ξ

(∞)t

)′and lace integrals computations:

h(X s) =3

2log2(4/3) .

29 / 32

Page 154: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

V. Comments

30 / 32

Page 155: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Why mathematical physics are hard to read for mathematicians?

Archaeology of Knowledge,1969

Concept of discursive formation

Mathematics and mathematical physics are distinct discursive formations ;different conceptions of units of meaning, etc.

31 / 32

Page 156: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Further research:

1 Extensions: eight-vertex model [Baxter], dimer model [Lieb]..

2 Hard core model ? Tridimensional ice ? Kari-Culik tilings ?

3 Transformation of entropy by subshifts operators ?

32 / 32

Page 157: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Further research:

1 Extensions: eight-vertex model [Baxter], dimer model [Lieb]..

2 Hard core model ? Tridimensional ice ? Kari-Culik tilings ?

3 Transformation of entropy by subshifts operators ?

32 / 32

Page 158: On exact computation of square ice entropy · On exact computation of square ice entropy Silv ere Ganglo LIP, ENS Lyon March 11, 2019 1/32. I. Representations of square ice 2/32.

Further research:

1 Extensions: eight-vertex model [Baxter], dimer model [Lieb]..

2 Hard core model ? Tridimensional ice ? Kari-Culik tilings ?

3 Transformation of entropy by subshifts operators ?

32 / 32


Recommended