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Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C Complexes of Hilbert C * -modules Svatopluk Krýsl Charles University, Prague, Czechia Nafpaktos, 8th July 2018
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Page 1: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Complexes of Hilbert C ∗-modules

Svatopluk Krýsl

Charles University, Prague, Czechia

Nafpaktos, 8th July 2018

Page 2: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Aim of the talk

Give a generalization of the framework for Hodge theory

Recall the Hodge theory for manifolds

Description of Hilbert C ∗-modules and Hodge theory of theirbundles

Example

Page 3: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Aim of the talk

Give a generalization of the framework for Hodge theory

Recall the Hodge theory for manifolds

Description of Hilbert C ∗-modules and Hodge theory of theirbundles

Example

Page 4: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Aim of the talk

Give a generalization of the framework for Hodge theory

Recall the Hodge theory for manifolds

Description of Hilbert C ∗-modules and Hodge theory of theirbundles

Example

Page 5: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Aim of the talk

Give a generalization of the framework for Hodge theory

Recall the Hodge theory for manifolds

Description of Hilbert C ∗-modules and Hodge theory of theirbundles

Example

Page 6: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Contents

1 Complexes on Topological vector spaces

2 The original Hodge theory for manifolds

3 Hodge theory for bundles of Hilbert C ∗-modules

Page 7: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

1 Complexes on Topological vector spaces

2 The original Hodge theory for manifolds

3 Hodge theory for bundles of Hilbert C ∗-modules

Page 8: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Complexes and Hodge theory for inner product spaces

E • = (E i )i∈Z a sequence of inner product spaces and

(di : E i → E i+1)i∈Z a sequence of continuous linear andadjointable maps (differentials) such that di+1di = 0 (complex).

Important objects: ∆i = d∗i di + di−1d∗i−1 ’Laplacians’

Hodge theory is the statement: E i ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i

(orthogonal sum)

This implies: H i (E •) = Ker di/Im di−1 ' Ker∆i

Ker∆i harmonic elements

Page 9: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Complexes and Hodge theory for inner product spaces

E • = (E i )i∈Z a sequence of inner product spaces and

(di : E i → E i+1)i∈Z a sequence of continuous linear andadjointable maps (differentials) such that di+1di = 0 (complex).

Important objects: ∆i = d∗i di + di−1d∗i−1 ’Laplacians’

Hodge theory is the statement: E i ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i

(orthogonal sum)

This implies: H i (E •) = Ker di/Im di−1 ' Ker∆i

Ker∆i harmonic elements

Page 10: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Complexes and Hodge theory for inner product spaces

E • = (E i )i∈Z a sequence of inner product spaces and

(di : E i → E i+1)i∈Z a sequence of continuous linear andadjointable maps (differentials) such that di+1di = 0 (complex).

Important objects: ∆i = d∗i di + di−1d∗i−1 ’Laplacians’

Hodge theory is the statement: E i ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i

(orthogonal sum)

This implies: H i (E •) = Ker di/Im di−1 ' Ker∆i

Ker∆i harmonic elements

Page 11: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Complexes and Hodge theory for inner product spaces

E • = (E i )i∈Z a sequence of inner product spaces and

(di : E i → E i+1)i∈Z a sequence of continuous linear andadjointable maps (differentials) such that di+1di = 0 (complex).

Important objects: ∆i = d∗i di + di−1d∗i−1 ’Laplacians’

Hodge theory is the statement: E i ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i

(orthogonal sum)

This implies: H i (E •) = Ker di/Im di−1 ' Ker∆i

Ker∆i harmonic elements

Page 12: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Complexes and Hodge theory for inner product spaces

E • = (E i )i∈Z a sequence of inner product spaces and

(di : E i → E i+1)i∈Z a sequence of continuous linear andadjointable maps (differentials) such that di+1di = 0 (complex).

Important objects: ∆i = d∗i di + di−1d∗i−1 ’Laplacians’

Hodge theory is the statement: E i ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i

(orthogonal sum)

This implies: H i (E •) = Ker di/Im di−1 ' Ker∆i

Ker∆i harmonic elements

Page 13: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Dagger categories

Dagger category = any category C with a dagger functor † which isa contravariant and idempotent endofunctor in C which is identityon objects (i.e., it preserves objects, reverse direction of morphismsand applied twice it is neutral)

Examples:Hilbert spaces: objects = Hilbert spaces, morphisms = linearcontinuous maps, and the adjoint of maps as †

bord-n category: objects = smooth oriented n-dimensionalmanifolds, morphisms between objects M, N = any oriented(n + 1)-manifold L which bords on the objects M and N, and theorientation reversion of L as †

TQFT is a specific functor from the cobord-n categories to themonoidal tensor category over a fixed Hilbert space.

Page 14: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Dagger categories

Dagger category = any category C with a dagger functor † which isa contravariant and idempotent endofunctor in C which is identityon objects (i.e., it preserves objects, reverse direction of morphismsand applied twice it is neutral)

Examples:Hilbert spaces: objects = Hilbert spaces, morphisms = linearcontinuous maps, and the adjoint of maps as †

bord-n category: objects = smooth oriented n-dimensionalmanifolds, morphisms between objects M, N = any oriented(n + 1)-manifold L which bords on the objects M and N, and theorientation reversion of L as †

TQFT is a specific functor from the cobord-n categories to themonoidal tensor category over a fixed Hilbert space.

Page 15: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Pseudoinverses on additive dagger categories

Let C be an additive category (each set of morphism is an abeliangroup and compositions are bilinear with respect to the abelianstructure) with dagger † (no compatibility necessary)

We say that a complex (E i , di )i in C is parametrix possessing if for∆i = d†i di + di−1d

†i−1, there are morphisms gi and pi in C such

that IdE i = gi∆i + pi = ∆igi + pi , dipi = 0 and d†i−1pi = 0.

Theorem (Krysl, Ann. Glob. Anal. Geom.): If (E i , di )i is aparametrix possessing complex in an additive dagger category, thengi are morphisms of complexes, i.e., gi+1di = digi .

Page 16: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Pseudoinverses on additive dagger categories

Let C be an additive category (each set of morphism is an abeliangroup and compositions are bilinear with respect to the abelianstructure) with dagger † (no compatibility necessary)

We say that a complex (E i , di )i in C is parametrix possessing if for∆i = d†i di + di−1d

†i−1, there are morphisms gi and pi in C such

that IdE i = gi∆i + pi = ∆igi + pi , dipi = 0 and d†i−1pi = 0.

Theorem (Krysl, Ann. Glob. Anal. Geom.): If (E i , di )i is aparametrix possessing complex in an additive dagger category, thengi are morphisms of complexes, i.e., gi+1di = digi .

Page 17: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Cohomology of complexes in inner product spaces

Theorem (Krysl, Ann. Glob. Anal. Geom.): Let E • = (E i , di )ibe a parametrix possessing complex with adjointable differentials inthe category of inner product spaces. Then pi+1di = 0 and thecohomology groups of E • are in a linear set-bijection with Ker∆i .

We say nothing about the continuity of this bijection.

Page 18: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Cohomology of complexes in inner product spaces

Theorem (Krysl, Ann. Glob. Anal. Geom.): Let E • = (E i , di )ibe a parametrix possessing complex with adjointable differentials inthe category of inner product spaces. Then pi+1di = 0 and thecohomology groups of E • are in a linear set-bijection with Ker∆i .

We say nothing about the continuity of this bijection.

Page 19: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

1 Complexes on Topological vector spaces

2 The original Hodge theory for manifolds

3 Hodge theory for bundles of Hilbert C ∗-modules

Page 20: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Suppose1) M a compact manifold, qi : E i → M, i ∈ Z, sequence of finite

rank vector bundles

2) Smooth functions with values in E i (sections: pi ◦ s = IdE i )have an inner product space topology: Equip M with aRiemannian metric g and each E i with a hermitian innerproduct h. Then (s, t) =

∫x∈M h(s(x), t(x))dµ(g)x

3) complex of differential operators di : C∞(E i )→ C∞(E i+1)complex is elliptic = symbol of ∆i is isomorphism out of thezero section

Theorem (Hodge, Fredholm, Weyl): Let (C∞(E i ), di )i be anelliptic complex on finite rank vector bundles (E i )i over a compactmanifold M. Then (C∞(E i ), di )i satisfies the Hodge theory and thecohomology groups H i (E •)(' Ker∆i ⊂ C∞(E i )) are finitedimensional.

Page 21: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Suppose1) M a compact manifold, qi : E i → M, i ∈ Z, sequence of finite

rank vector bundles2) Smooth functions with values in E i (sections: pi ◦ s = IdE i )

have an inner product space topology: Equip M with aRiemannian metric g and each E i with a hermitian innerproduct h. Then (s, t) =

∫x∈M h(s(x), t(x))dµ(g)x

3) complex of differential operators di : C∞(E i )→ C∞(E i+1)complex is elliptic = symbol of ∆i is isomorphism out of thezero section

Theorem (Hodge, Fredholm, Weyl): Let (C∞(E i ), di )i be anelliptic complex on finite rank vector bundles (E i )i over a compactmanifold M. Then (C∞(E i ), di )i satisfies the Hodge theory and thecohomology groups H i (E •)(' Ker∆i ⊂ C∞(E i )) are finitedimensional.

Page 22: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Suppose1) M a compact manifold, qi : E i → M, i ∈ Z, sequence of finite

rank vector bundles2) Smooth functions with values in E i (sections: pi ◦ s = IdE i )

have an inner product space topology: Equip M with aRiemannian metric g and each E i with a hermitian innerproduct h. Then (s, t) =

∫x∈M h(s(x), t(x))dµ(g)x

3) complex of differential operators di : C∞(E i )→ C∞(E i+1)complex is elliptic = symbol of ∆i is isomorphism out of thezero section

Theorem (Hodge, Fredholm, Weyl): Let (C∞(E i ), di )i be anelliptic complex on finite rank vector bundles (E i )i over a compactmanifold M. Then (C∞(E i ), di )i satisfies the Hodge theory and thecohomology groups H i (E •)(' Ker∆i ⊂ C∞(E i )) are finitedimensional.

Page 23: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Suppose1) M a compact manifold, qi : E i → M, i ∈ Z, sequence of finite

rank vector bundles2) Smooth functions with values in E i (sections: pi ◦ s = IdE i )

have an inner product space topology: Equip M with aRiemannian metric g and each E i with a hermitian innerproduct h. Then (s, t) =

∫x∈M h(s(x), t(x))dµ(g)x

3) complex of differential operators di : C∞(E i )→ C∞(E i+1)complex is elliptic = symbol of ∆i is isomorphism out of thezero section

Theorem (Hodge, Fredholm, Weyl): Let (C∞(E i ), di )i be anelliptic complex on finite rank vector bundles (E i )i over a compactmanifold M. Then (C∞(E i ), di )i satisfies the Hodge theory and thecohomology groups H i (E •)(' Ker∆i ⊂ C∞(E i )) are finitedimensional.

Page 24: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

H i (E •) = Ker di/Im di−1

Im di−1 ⊂ C∞(E i ) are closed

Cohomology groups are Hausdorff

The bijection between cohomology and harmonic element ishomeomorphism

Page 25: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

H i (E •) = Ker di/Im di−1

Im di−1 ⊂ C∞(E i ) are closed

Cohomology groups are Hausdorff

The bijection between cohomology and harmonic element ishomeomorphism

Page 26: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

H i (E •) = Ker di/Im di−1

Im di−1 ⊂ C∞(E i ) are closed

Cohomology groups are Hausdorff

The bijection between cohomology and harmonic element ishomeomorphism

Page 27: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

H i (E •) = Ker di/Im di−1

Im di−1 ⊂ C∞(E i ) are closed

Cohomology groups are Hausdorff

The bijection between cohomology and harmonic element ishomeomorphism

Page 28: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

1 Complexes on Topological vector spaces

2 The original Hodge theory for manifolds

3 Hodge theory for bundles of Hilbert C ∗-modules

Page 29: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Hilbert C ∗-modules

1) (A, || ||, ∗) a C ∗-algebra, i.e., A is associative algebra, || || is anorm and ∗ is an linear idempotent map such that||aa∗|| = ||a||2 and (A, || ||) is Cauchy complete

2) A+ = {a| a = a∗ and sp(a) ⊂ [0,∞)} wheresp(a) = {λ| a− λ1 does not have inverse}

3) Hilbert A-module = (R, (, )) is complex vector space which isa right A-module and (, ) : R × R → A is A-sesquilinear,hermitian ((u, v) = (v , u)∗), positive definite (v , v) ∈ A+,(v , v) = 0 implies v = 0 and (R, | |) is complete where|v | =

√||(v , v)||

Page 30: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Hilbert C ∗-modules

1) (A, || ||, ∗) a C ∗-algebra, i.e., A is associative algebra, || || is anorm and ∗ is an linear idempotent map such that||aa∗|| = ||a||2 and (A, || ||) is Cauchy complete

2) A+ = {a| a = a∗ and sp(a) ⊂ [0,∞)} wheresp(a) = {λ| a− λ1 does not have inverse}

3) Hilbert A-module = (R, (, )) is complex vector space which isa right A-module and (, ) : R × R → A is A-sesquilinear,hermitian ((u, v) = (v , u)∗), positive definite (v , v) ∈ A+,(v , v) = 0 implies v = 0 and (R, | |) is complete where|v | =

√||(v , v)||

Page 31: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Hilbert C ∗-modules

1) (A, || ||, ∗) a C ∗-algebra, i.e., A is associative algebra, || || is anorm and ∗ is an linear idempotent map such that||aa∗|| = ||a||2 and (A, || ||) is Cauchy complete

2) A+ = {a| a = a∗ and sp(a) ⊂ [0,∞)} wheresp(a) = {λ| a− λ1 does not have inverse}

3) Hilbert A-module = (R, (, )) is complex vector space which isa right A-module and (, ) : R × R → A is A-sesquilinear,hermitian ((u, v) = (v , u)∗), positive definite (v , v) ∈ A+,(v , v) = 0 implies v = 0 and (R, | |) is complete where|v | =

√||(v , v)||

Page 32: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Closed images of Laplacians implies Hausdorff cohomologies

Hilbert C ∗-bundles = Banach bundles with fibers a fixed HilbertC ∗-module R and transition maps to the group of C ∗- automorph.of fibers - homeomorphisms T such that T (ra) = [T (r)]a

Finitely generated = fiber is a finite linear combination∑m

i=1 riai ,ri ∈ R, ai ∈ A

Projective = whenever R is embedded into S , S = R ⊕ R ′ OGsplitting

Theorem (S. Krysl, Ann. Glob. Anal. Geom.): Let (E i → M)ibe a sequence of finitely generated projective C ∗-bundles overcompact manifold M and (C∞(E i ), di )i be an elliptic complex ofC ∗-operators such that the Laplacians have closed images. Thenthe Hodge theory holds for the complex and the cohomology groupsare finitely generated projective Hilbert C ∗-modules.

Page 33: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Closed images of Laplacians implies Hausdorff cohomologies

Hilbert C ∗-bundles = Banach bundles with fibers a fixed HilbertC ∗-module R and transition maps to the group of C ∗- automorph.of fibers - homeomorphisms T such that T (ra) = [T (r)]a

Finitely generated = fiber is a finite linear combination∑m

i=1 riai ,ri ∈ R, ai ∈ A

Projective = whenever R is embedded into S , S = R ⊕ R ′ OGsplitting

Theorem (S. Krysl, Ann. Glob. Anal. Geom.): Let (E i → M)ibe a sequence of finitely generated projective C ∗-bundles overcompact manifold M and (C∞(E i ), di )i be an elliptic complex ofC ∗-operators such that the Laplacians have closed images. Thenthe Hodge theory holds for the complex and the cohomology groupsare finitely generated projective Hilbert C ∗-modules.

Page 34: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Closed images of Laplacians implies Hausdorff cohomologies

Hilbert C ∗-bundles = Banach bundles with fibers a fixed HilbertC ∗-module R and transition maps to the group of C ∗- automorph.of fibers - homeomorphisms T such that T (ra) = [T (r)]a

Finitely generated = fiber is a finite linear combination∑m

i=1 riai ,ri ∈ R, ai ∈ A

Projective = whenever R is embedded into S , S = R ⊕ R ′ OGsplitting

Theorem (S. Krysl, Ann. Glob. Anal. Geom.): Let (E i → M)ibe a sequence of finitely generated projective C ∗-bundles overcompact manifold M and (C∞(E i ), di )i be an elliptic complex ofC ∗-operators such that the Laplacians have closed images. Thenthe Hodge theory holds for the complex and the cohomology groupsare finitely generated projective Hilbert C ∗-modules.

Page 35: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Closed images of Laplacians implies Hausdorff cohomologies

Hilbert C ∗-bundles = Banach bundles with fibers a fixed HilbertC ∗-module R and transition maps to the group of C ∗- automorph.of fibers - homeomorphisms T such that T (ra) = [T (r)]a

Finitely generated = fiber is a finite linear combination∑m

i=1 riai ,ri ∈ R, ai ∈ A

Projective = whenever R is embedded into S , S = R ⊕ R ′ OGsplitting

Theorem (S. Krysl, Ann. Glob. Anal. Geom.): Let (E i → M)ibe a sequence of finitely generated projective C ∗-bundles overcompact manifold M and (C∞(E i ), di )i be an elliptic complex ofC ∗-operators such that the Laplacians have closed images. Thenthe Hodge theory holds for the complex and the cohomology groupsare finitely generated projective Hilbert C ∗-modules.

Page 36: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Compactness trick not possible. The proof is based on regularity(G. Kasparov, Y. Solovyov), results of A. S. Mishchenko and A. T.Fomenko from ’70

The assumption on the closed images seems to be hard to verify inspecific cases.

Page 37: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Compactness trick not possible. The proof is based on regularity(G. Kasparov, Y. Solovyov), results of A. S. Mishchenko and A. T.Fomenko from ’70The assumption on the closed images seems to be hard to verify inspecific cases.

Page 38: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

Compact operators

Let A = CH be the algebra of compact operators on a Hilbertspace, then extension of the image of ∆i to Sobolev completions isclosed, i.e.,Theorem (S. Krysl, Jour. Geom. Phys.): Let (E i → M)i be asequence of finitely generated projective CH-bundles over compactmanifold M and (C∞(E i ), di )i be an elliptic complex ofC ∗-operators. Then the Hodge theory holds for them and thecohomology groups of the complex are finitely generated projectiveHilbert C ∗-modules. Especially,1) C∞(E i ) ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i

2) H i (E •) ' Ker∆i is finitely generated over CH3) Im∆i ' Im d∗i ⊕ Im di−1

4) Ker di ' Ker∆i ⊕ Im di−1 and Ker d∗i ' Ker∆i ⊕ Im d∗i+1

Underlying result [Bakic, Guljas].

Page 39: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

An example from bundles induced by representations

(M2n, ω) real symplectic manifold, Mp(2n,R) double cover of thesymplectic group, S the complexified Shale–Weil representation onthe Hilbert space H = L2(Cn), S the Shale–Weil bundle induced byS over manifold M

Global trivialization of S, product connection ∇ on S,S i =

∧i T ∗M ⊗ S, complex d• of differential operators (twisteddeRham ops). Bundles can be viewed as a Hilbert CH-bundle.

Theorem (S. Krysl): If M is compact than d• satisfies the Hodgetheory. In particular, C∞(S i ) ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i andH i (d•) ' Ker∆i Further the cohomological groups areCH-isomorphic to Hk

deRham(M)⊗ H. In particular their rank equalsto the Betti numbers.

Page 40: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

An example from bundles induced by representations

(M2n, ω) real symplectic manifold, Mp(2n,R) double cover of thesymplectic group, S the complexified Shale–Weil representation onthe Hilbert space H = L2(Cn), S the Shale–Weil bundle induced byS over manifold M

Global trivialization of S, product connection ∇ on S,S i =

∧i T ∗M ⊗ S, complex d• of differential operators (twisteddeRham ops). Bundles can be viewed as a Hilbert CH-bundle.

Theorem (S. Krysl): If M is compact than d• satisfies the Hodgetheory. In particular, C∞(S i ) ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i andH i (d•) ' Ker∆i Further the cohomological groups areCH-isomorphic to Hk

deRham(M)⊗ H. In particular their rank equalsto the Betti numbers.

Page 41: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

An example from bundles induced by representations

(M2n, ω) real symplectic manifold, Mp(2n,R) double cover of thesymplectic group, S the complexified Shale–Weil representation onthe Hilbert space H = L2(Cn), S the Shale–Weil bundle induced byS over manifold M

Global trivialization of S, product connection ∇ on S,S i =

∧i T ∗M ⊗ S, complex d• of differential operators (twisteddeRham ops). Bundles can be viewed as a Hilbert CH-bundle.

Theorem (S. Krysl): If M is compact than d• satisfies the Hodgetheory. In particular, C∞(S i ) ' Im di−1 ⊕ Im d∗i ⊕ Ker∆i andH i (d•) ' Ker∆i Further the cohomological groups areCH-isomorphic to Hk

deRham(M)⊗ H. In particular their rank equalsto the Betti numbers.

Page 42: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

[BakGulOpThy] Bakić, D., Guljaš, B., Operators on HilbertH∗-modules, J. Oper. Theory 46 (2001), no. 1, 123–137.

[FomenkoMishchenkoIzvNauk] Fomenko, A., Mishchenko, A., Theindex of elliptic operators over C ∗-algebras, Izv. Akad. NaukSSSR Ser. Mat. 43 (1979), no. 4, 831–859, 967.

[SKAGAG] Krýsl, S., Hodge theory for self-adjoint parametrixpossessing complexes over C ∗-algebras, Annals Glob. Anal.Geom. Vol. 47 (2015), no. 4, 359–372.

[SKGeom.Phys2016] Krýsl, S., Elliptic complexes over C ∗-algebrasof compact operators, Journal of Geometry and Physics, Vol.101 (2016), 27–37.

[MishchenkoRMS] Mishchenko, A., Banach algebras,pseudodifferential operators, and their application to K-theory.Russ. Math. Surv. 34 (1979), no. 6, 77–91.

[SchickNYMath] Schick, T., L2-index theorems, KK -theory, andconnections, New York J. Math. 11, 387-443 (2005).

Page 43: ComplexesofHilbert C -modules - Univerzita Karlovakrysl/ICT.pdf · Complexes on Topological vector spacesThe original Hodge theory for manifoldsHodge theory for bundles of Hilbert

Complexes on Topological vector spaces The original Hodge theory for manifolds Hodge theory for bundles of Hilbert C∗-modules

[ShaleTrans.AMS62] Shale, D., Linear symmetries of free bosonfields, Trans. Amer. Math. Soc. 103 (1962), 149–167.

[AGAG] Troitsky, E., The index of equivariant elliptic operators overC ∗-algebras. Ann. Global Anal. Geom. 5 (1987), no. 1, 3–22.

[WeilActa.Math.64] Weil, A., Sur certains groupes d’opérateursunitaires, Acta Math. 111 (1964), 143–211.


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