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Quantum Cosmology with Distorted Gravity

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Quantum Cosmology with Distorted Gravity Remo Garattini Università di Bergamo I.N.F.N. - Sezione di Milano Cagliari 18 Marzo 2016
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Page 1: Quantum Cosmology with Distorted Gravity

Quantum Cosmologywith

Distorted Gravity

Remo GarattiniUniversità di Bergamo

I.N.F.N. - Sezione di Milano

Cagliari 18 Marzo 2016

Page 2: Quantum Cosmology with Distorted Gravity

Plan of the Talk

•Building the Wheeler-DeWitt Equation•The Wheeler-DeWitt Equation as a Sturm-Liouville problem•Relaxing the Lorentz Symmetry in a MSS approach for a FLRW model.•The Cosmological Constant as a Zero Point EnergyComputation in the Gravity’s Rainbow context

•Conclusions and Outlooks

Page 3: Quantum Cosmology with Distorted Gravity

34 4 31 2 2 82 Newton's Constant Cosmological Constant

matterS d x g R d x g K S G

G

M M

Relevant Action for Quantum Cosmology

Page 4: Quantum Cosmology with Distorted Gravity

34 4 31 122 matterS d x g R d x g K S

M M

Relevant Action for Quantum Cosmology

2 2 2

33

2 2

1

j

kk j

i i jiji ij

NN N N N N Ng g

N g N N NgN N

ADM Decomposition

2 2 2ds

is the lapse function is the shift function

i i j jij

i

g dx dx N dt g N dt dx N dt dx

N N

1 2

ijij ij i j j i ijK g N N K K g

N

Page 5: Quantum Cosmology with Distorted Gravity

33 2 3

3

3

1 22

Legendre Transformation

2 2 0 Classical Constraint Invariance by time2

ijij matterI

I

ii

ij klijkl

S dtd xN g K K K R S S

H d x N N H

gG R

H H

H

|

reparametrization2 0 Classical Constraint Gauss Lawi ij

j H

2 2 22

33

2 2

1

ds

j

kk j

i i jiji ij

NN N N N N Ng g g dx dx

N g N N NgN N

Page 6: Quantum Cosmology with Distorted Gravity

Wheeler-De Witt EquationB. S. DeWitt, Phys. Rev.160, 1113 (1967).

2 2 02

ij klijkl ij

gG R g

• Gijkl is the super-metric,• R is the scalar curvature in 3-dim.

2 2 2 2 23ds N dt a t d

2 2

2 42 2

9 04 3

qH a a a aa a a G

Formal Schrödinger Equation with zero eigenvalue whose solution is a linear combination ofAiry’s functions (q=-1 Vilenkin Phys. Rev. D 37, 888 (1988).) containing expanding solutions

Example:WDW for Tunneling

Page 7: Quantum Cosmology with Distorted Gravity

Wheeler-De Witt EquationB. S. DeWitt, Phys. Rev.160, 1113 (1967).

E=0 is highly degenerate

Sturm-Liouville Eigenvalue Problem

2

2 42

1 9 04 3

qqH a a a a a E a E

a a a G

0

* Normalization with weight b

a

d dp x q x w x y xdx dx

w x y x y x dx w x

2 2

2 43 3 2 2 3

q q qp x a t q x a t w x a t y x aG G

4 *

0

qa a a da

Page 8: Quantum Cosmology with Distorted Gravity

Wheeler-De Witt EquationB. S. DeWitt, Phys. Rev.160, 1113 (1967).

Sturm-Liouville Eigenvalue Problem Variational procedure

2

2 42

1 9 04 3

qqH a a a a a

a a a G

*min

*

b

aby x

a

d dy x p x q x y x dxdx dx

w x y x y x dx

0y a y b

Rayleigh-RitzVariational Procedure

Page 9: Quantum Cosmology with Distorted Gravity

Wheeler-De Witt EquationB. S. DeWitt, Phys. Rev.160, 1113 (1967).

Sturm-Liouville Eigenvalue Problem Variational procedure

2

2 42

1 9 04 3

qqH a a a a a

a a a G

22

20

4

0

3*23 min

3 2*

q q

aq

d da a a a dada da G

Ga a a da

0 0 0 De Witt Condition

Rayleigh-RitzVariational Procedure

2

0 0 for example for q=0

exp No Solutiona a

Page 10: Quantum Cosmology with Distorted Gravity

Relaxing Lorentz symmetryHořava-Lifshitz theory UV Completion, problems with scalar graviton in IR

Varying Speed of Light Cosmology Solve problems in the Inflationary phase(horizon,flatness, particle production)

Gravity’s Rainbow Like VSL. Moreover it allows finite calculation to one loop.The set of the Rainbow’s functions is too large. A selection procedure is necessary

At low energy all these models describe GR

Page 11: Quantum Cosmology with Distorted Gravity

Gravity’s Rainbow

2 2 2 2 21 2

1 2/ 0 / 0

/ /

lim / lim / 1P P

P P

P PE E E E

E g E E p g E E m

g E E g E E

Doubly Special Relativity

G. Amelino-Camelia, Int.J.Mod.Phys. D 11, 35 (2002); gr-qc/001205.G. Amelino-Camelia, Phys.Lett. B 510, 255 (2001); hep-th/0012238.

Curved Space Proposal Gravity’s Rainbow[J. Magueijo and L. Smolin, Class. Quant. Grav. 21, 1725 (2004) arXiv:gr-qc/0305055].

2 2 2 22 2 2 2

2 2 21 2 22

2

0 0 0

sin/ / /

1 /

exp 2 is the redshift function

is the shape function Condition ,

P P PP

N r dt dr r rds d db rg E E g E E g E E

g E Er

N r r r

b r b r r r r

Page 12: Quantum Cosmology with Distorted Gravity

Gravity’s Rainbow Application to Inflation[R. Garattini and M. Sakellariadou, Phys. Rev. D 90 (2014) 4, 043521; arXiv:1212.4987 [gr-qc]]

22 2 2

2 22 2

1 2

2 22 22

2

3 /1 0

2 / 3 /

3 41 0 12 3

P

P P

effeff

g E Eq aa aa a a Gg E E g E E

aq Ga a Va a a G

2 22 2 2

32 21 2

Distorted / /

N t a tds dt d FLRW metric

g E Ep g E Ep

Page 13: Quantum Cosmology with Distorted Gravity

22 2 22 2

2 21 2

3 /1 0

2 / 3 /P

P P

g E Eq aa aa a a Gg E E g E E

But we can go beyond this…indeed if thenE E a t

2

2 2 2 21 2

1 33 / , where , 1 2ijij P

aK K K g E E f a t a f a t a a t A t A t a tN t a

Gravity’s Rainbow Application to Hořava-Lifshitz theory[R. Garattini and E.N.Saridakis, Eur.Phys.J. C75 (2015) 7, 343; arXiv:1411.7257 [gr-qc]]

2

2

/1/

P

P P

dg E a t E dEA tdE dag E a t E E

Page 14: Quantum Cosmology with Distorted Gravity

2 2 2 2

2 22 2 2then using the "normal" dispersion relation and P

P P

k k k kE Ea t a l G

21

2 422 1 22 4

If we fix / , =1

/ 1

P

PP P

g E E f a t a

E a t E a tg E E c c

E E

2 2 2 2

22 2 4 2

0 0

16 256 16 256/ 1 1 Pb G G b R Rg E E

a t a t R R

Potential part of the Projectable Hořava-Lifshitz theorywithout detailed balancedCondition z=3

Gravity’s Rainbow Application to Hořava-Lifshitz theory[R. Garattini and E.N.Saridakis, Eur.Phys.J. C75 (2015) 7, 343; arXiv:1411.7257 [gr-qc]]

It is possible to build a mapAlso for SSM

Page 15: Quantum Cosmology with Distorted Gravity

10 12 1 g g 0b c GR

Applying the Rayleigh-Ritz procedure we can find candidate eigenvaluesdepending on the combination of the coupling constants[R. G., P.R.D 86 123507 (2012) 7, 343; arXiv:0912.0136 [gr-qc]]

Gravity’s Rainbow Application to Hořava-Lifshitz theory[R. Garattini and E.N.Saridakis, Eur.Phys.J. C75 (2015) 7, 343; arXiv:1411.7257 [gr-qc]]

Page 16: Quantum Cosmology with Distorted Gravity
Page 17: Quantum Cosmology with Distorted Gravity

The WDW equation becomes

Albrecht, Barrow, Harko, Maguejio, Moffat..

MSS in a VSL CosmologyR.G. and M.De Laurentis, arXiv:1503.03677

Page 18: Quantum Cosmology with Distorted Gravity

MSS in a VSL CosmologyR.G. and M.De Laurentis, arXiv:1503.03677

0 PSetting a kl

Page 19: Quantum Cosmology with Distorted Gravity

A Brief Mention to GUP

[R. Garattini and Mir Faizal; N.P. B 905 (2016) 313 arXiv:1510.04423 [gr-qc]]

Flat space

Deformed Momentum

Deformed U.P.

Trial Wave Function

Higher Order Derivative

Page 20: Quantum Cosmology with Distorted Gravity

From Mini-SuperSpaceto

Field Theory in 3+1 Dimensions

The Cosmological Constantas a Zero Point Energy

Calculation

Generalization

Page 21: Quantum Cosmology with Distorted Gravity

Solve this infinite dimensional PDE with a VariationalApproach without matter fields contribution

is a trial wave functional of the gaussian typeSchrödinger Picture

Spectrum of depending on the metricEnergy (Density) Levels

Wheeler-De Witt EquationB. S. DeWitt, Phys. Rev.160, 1113 (1967).

3

1

Tij j

D h h d x h

V D h h h

D h D h D D h J

InducedCosmological‘‘Constant’’

Page 22: Quantum Cosmology with Distorted Gravity

Eliminating Divergences usingGravity’s Rainbow

[R.G. and G.Mandanici, Phys. Rev. D 83, 084021 (2011), arXiv:1102.3803 [gr-qc]]

3 2

1,2 1323

2 2

1ˆ 2 , ,4 2

ijkl

ijkl ijkl

g E g Ed x gG K x x K x x

V g E g E

42

, : (Propagator)2

ij kl

ijkl

h x h yK x y

g E

2

Modified Lichnerowicz operator

Standard Lichnerowicz operator

4

2

aia j ijij

jl a aij ijkl ia j ja iij

h R h Rh

h h R h R h R h

2

2 22

E= ijijh h

g E

One loop Graviton Contribution

Page 23: Quantum Cosmology with Distorted Gravity

We can define an r-dependent radial wave number

22 2

2 22

1, ,

/nl

nl iP

l lEk r l E m r r r xg E E r

21 2 2 3

22 2 2 3

3 ' 36 12 2

' 36 12 2

b r b r b rm r

r r r r

b r b r b rm r

r r r r

3222

1 22 21 2*

1 ( / ) ( / ) ( )3 ( / )8

ii P P i i

i i PE

EdE g E E g E E m r dEdE g EG E

2

2

122 2 2

18 16 i

iim r

i i

dG m r

Standard Regularization

Eliminating Divergences usingGravity’s Rainbow

[R.G. and G.Mandanici, Phys. Rev. D 83, 084021 (2011), arXiv:1102.3803 [gr-qc]]

Page 24: Quantum Cosmology with Distorted Gravity

Gravity’s Rainbow and the Cosmological ConstantR.G. and G.Mandanici, Phys. Rev. D 83, 084021 (2011), arXiv:1102.3803 [gr-qc]

1

2

Popular Choice...... Not Promising

/ 1

/ 1

n

PP

P

Eg E EE

g E E

Failure of Convergence

2

1 2

2

/ exp 1

/ 1

PP P

P

E Eg E EE E

g E E

2 2 2 2 21 2 0 0

- - -

/ P

Minkowski de Sitter Anti de Sitter

m r m r m r x m r E

Page 25: Quantum Cosmology with Distorted Gravity

Conclusions and Outlooks• The Wheeler De Witt equation can be considered as a

Sturm-Liouville Problem Rayleigh-Ritz Variationalprocedure.

• In ordinary GR, we need a cut-off or a regularization/renormalization scheme.

• Application of Gravity’s Rainbow can be considered tocompute divergent quantum observables.

• Neither Standard Regularization nor Renormalization are required. This also happens in NonCommutativegeometries. A tool for ZPE Computation

• A connection between Horava-Lifshits theory withoutdetailed balanced condition and with projectability and Gravity’s Rainbow seems possible, at least in a FLRW metric. This is expected also for a VSL

• Repeating the above procedure for a SSM• Technical Problems with Kerr and other complicated

metrics. Comparison with Observation.


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