Secondary invariants for two-cocycle twists
|
|
- Bertha Lewis
- 6 years ago
- Views:
Transcription
1 Secondary invariants for two-cocycle twists Sara Azzali (joint work with Charlotte Wahl) Institut für Mathematik Universität Potsdam Villa Mondragone, June 17, 2014 Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
2 Overview Outline and keywords context: index theory of elliptic operators primary: index,indexclass secondary: eta,rho,analytictorsion... Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
3 Overview Outline and keywords context: index theory of elliptic operators primary: index,indexclass secondary: eta,rho,analytictorsion... on the universal covering M of a closed manifold projectively invariant operators 2-cocycle twists Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
4 Overview Outline and keywords context: index theory of elliptic operators primary: index,indexclass secondary: eta,rho,analytictorsion... on the universal covering M of a closed manifold projectively invariant operators 2-cocycle twists in physics: magnetic fields, quantum Hall effect in geometry: main ideas (Gromov, Mathai) c H 2 (BΓ, R) natural C -bundles of small curvature pairing without the extension properties Joint with Charlotte Wahl: define η and ρ for Dirac operators twisted by a 2-cocycle use ρ to distinguish geometric structures (positive scalar curvature..) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
5 Introduction Spectral invariants of elliptic operators Primary: the index D elliptic, Dirac type on M, closed manifold in particular: 1 d + d on a Riemannian manifold M 2 D/ the Dirac on a spin manifold M. spec D = {λ j } j N primary ind D := dim Ker D dim Coker D Z Theorem (Atiyah Singer 1963) ind D + = Â(M) ch E/S M Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
6 Primary: the index Introduction Spectral invariants of elliptic operators D elliptic, Dirac type on M, closed manifold in particular: 1 d + d on a Riemannian manifold M 2 D/ the Dirac on a spin manifold M. spec D = {λ j } j N primary ind D := dim Ker D dim Coker D Z Theorem (Atiyah Singer 1963) ind D + = Â(M) ch E/S 1 d + d on Λ +/ ind(d + )=sign(m) = 2 D/ on spinors ind D/ + = Â(M) M M M L(M) Hirzebruch s theorem Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
7 Introduction Secondary: the eta invariant Spectral asymmetry Atiyah Patodi Singer, 1974: for D = D (dim M =odd) η(d, s) = 0 λ j spec D η(d) :=η(d, s) s=0 = sign(λ j ) λ j s 0 λ j spec D sign(λ j ) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
8 Introduction Secondary: the eta invariant Spectral asymmetry Atiyah Patodi Singer, 1974: for D = D (dim M =odd) M = W η(d, s) = 0 λ j spec D η(d) :=η(d, s) s=0 = sign(λ j ) λ j s 0 λ j spec D sign(λ j ) Atiyah Patodi Singer theorem (1974) ind D W = Â(W ) ch E/S 1 2 (η(d W )+dim Ker D W ) W η(d) spectral contribution, non-local! M = S 1, η( i d dx + a) = { 0, a Z 2a 1, a (0, 1) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
9 Secondary: rho invariants Introduction rho invariants and classification of positive scalar curvature metrics Atiyah Patodi Singer: α: Γ U(k) flatbundle ρ α (D) :=η(d k ) η(d α ) Cheeger Gromov: ρ Γ (D) :=η Γ ( D) η(d) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
10 Introduction rho invariants and classification of positive scalar curvature metrics Secondary: rho invariants Atiyah Patodi Singer: α: Γ U(k) flatbundle ρ α (D) :=η(d k ) η(d α ) Cheeger Gromov: ρ Γ (D) :=η Γ ( D) η(d) Property: ρ can distinguish geometric structures M closed spin D/ 2 g = scal g then scal g > 0 D/ g invertible Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
11 Secondary: rho invariants Introduction rho invariants and classification of positive scalar curvature metrics Atiyah Patodi Singer: α: Γ U(k) flatbundle ρ α (D) :=η(d k ) η(d α ) Cheeger Gromov: ρ Γ (D) :=η Γ ( D) η(d) Property: ρ can distinguish geometric structures M closed spin D/ 2 g = scal g then scal g > 0 D/ g invertible (g t ) t [0,1] R + (M) :={g metric on TM scal g > 0} 0= W Â(W )+ 1 2 η(d/ g 0 ) 1 2 η(d/ g 1 ) 0= W Â(W ) ch α η(d/α g 0 ) 1 2 η(d/α g 1 ) it gives a map ρ(d/): π 0 (R + (M)) R Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
12 Introduction Role of primary vs. secondary invariants Role of index and rho: positive scalar curvature M closed spin manifold D/ 2 g = scal g. R + (M) ={g metric on TM scal g > 0} ind D/ is an obstruction (ind D/ 0 R + (M) = ) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
13 Introduction Role of primary vs. secondary invariants Role of index and rho: positive scalar curvature M closed spin manifold D/ 2 g = scal g. R + (M) ={g metric on TM scal g > 0} ind D/ is an obstruction (ind D/ 0 R + (M) = ) ρ(d/) can distinguish non-cobordant metrics, assuming R + (M), Theorem: (Piazza Schick, Botvinnik Gilkey) R + (M) dim M =4k +3, k > 0 π1(m) hastorsion Theorem: (Piazza Schick) infinitely many non-cobordant {g j } j N R + (M) ρ(d/ gi ) ρ(d/ gj ) i j π1(m) torsionfree,andsatisfiesbaum Connes ρ(d/ g )=0forg R + (M) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
14 Projectively invariant operators Projective actions π : M M universal covering, Γ = π1 (M) Exemple: R n R n /Z n = T n Γ-invariant: Dγ = γ D γ Γ Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
15 Projectively invariant operators Projective actions π : M M universal covering, Γ = π1 (M) Exemple: R n R n /Z n = T n Γ-invariant: Dγ = γ D γ Γ projectively Γ-invariant : BT γ = T γ B γ Γ, where T γ T γ = σ(γ,γ )T γγ, T e = I then σ :Γ Γ U(1) is a multiplier, i.e.[σ] H 2 (Γ, U(1)) σ(γ 1,γ 2 )σ(γ 1 γ 2,γ 3 )=σ(γ 1,γ 2 γ 3 )σ(γ 2,γ 3 ) σ(e,γ)=σ(γ,e) =1 Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
16 Typical construction Projectively invariant operators Example: the magnetic Laplacian π : M M universal covering, Γ = π1 (M). On the trivial line L = M C M consider = d + ia, whereda Ω 2 ( M, R) isγ-invariant:da = π ω, ω Ω 2 (M, R) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
17 Projectively invariant operators Example: the magnetic Laplacian Typical construction π : M M universal covering, Γ = π1 (M). On the trivial line L = M C M consider Then: = d + ia, whereda Ω 2 ( M, R) isγ-invariant:da = π ω, ω Ω 2 (M, R) γ A A = dψ γ σ(γ,γ )=exp(iψ γ (γ x 0 )) is a multiplier H A =(d + ia) (d + ia), called the magnetic Laplacian, is projectively invariant with respect to T γ u =(γ 1 ) e iψγ u, u L 2 ( M) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
18 Projectively invariant operators Example: the magnetic Laplacian Typical construction π : M M universal covering, Γ = π1 (M). On the trivial line L = M C M consider Then: = d + ia, whereda Ω 2 ( M, R) isγ-invariant:da = π ω, ω Ω 2 (M, R) γ A A = dψ γ σ(γ,γ )=exp(iψ γ (γ x 0 )) is a multiplier H A =(d + ia) (d + ia), called the magnetic Laplacian, is projectively invariant with respect to T γ u =(γ 1 ) e iψγ u, u L 2 ( M) Remark: the construction can be done starting from c H 2 (BΓ, R) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
19 Projectively invariant operators Two-cocycle twists Properties and the L 2 -index Properties of B = D : (Gromov, Mathai) BT γ = T γ B B is affiliated to B(L 2 ( M)) T N(Γ,σ) L 2 (F) Q B(L 2 ( M)) T, tr Γ,σ (Q) = F k Q(x, x) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
20 Projectively invariant operators Two-cocycle twists Properties and the L 2 -index Properties of B = D : (Gromov, Mathai) BT γ = T γ B B is affiliated to B(L 2 ( M)) T N(Γ,σ) L 2 (F) Q B(L 2 ( M)) T, tr Γ,σ (Q) = F k Q(x, x) at the level of Schwartz kernels, if QT γ = T γ Q,then e iψγ(x) k Q (γx,γy)e iψγ(y) = k Q (x, y) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
21 Projectively invariant operators Two-cocycle twists Properties and the L 2 -index Properties of B = D : (Gromov, Mathai) BT γ = T γ B B is affiliated to B(L 2 ( M)) T N(Γ,σ) L 2 (F) Q B(L 2 ( M)) T, tr Γ,σ (Q) = F k Q(x, x) at the level of Schwartz kernels, if QT γ = T γ Q,then e iψγ(x) k Q (γx,γy)e iψγ(y) = k Q (x, y) Atiyah s L 2 -theorem (Gromov) ind Γ,σ B = Â(M) ch(e/s) e ω where ω = f c, f : M BΓ classifyingmap M Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
22 Projectively invariant operators Bundles of small curvature Making the curvature small Mathai s constructions: given c H 2 (BΓ, R) Mischchenko-type C (Γ,σ)-bundle V C (Γ,σ) M whose curvature is ω I idea: pass to σ s = e isψ corresponds to curvature = sω I Theorem: (Mathai) For c H 2 (BΓ, R), sign(m, c) := Proof: tr Γ,σ ind(d sign VC (Γ,σ) )= j M L(M) f c are homotopy invariants. s j L(M) ω j j! M Hilsum Skandalis s theorem: ind(d sign VC (Γ,σ) ) is a homotopy invariant, for s small enough Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
23 Projectively invariant operators What are eta and rho? Eta and rho for 2-cocycle twists Questions: 1 define η c (D)? (easy) 2 prove an index theorem for manifolds with boundary 3 find interesting ρ c (D) 4 relate them with higher rho-invariants (defined by Lott, Leichtnam Piazza) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
24 Definitions Projectively invariant operators What are eta and rho? Let τ s be a family of positive (finite) traces on C (Γ,σ s )s.t. τ s (δ γ )=τ s (χ(γ)δ γ ), for any homomorphism χ: Γ U(1) ητ c s (D) := 1 π 0 Tr τ (D VC (Γ,σ) e td V C (Γ,σ) ) dt t ρ c τ s (D) = same expression, with τ s delocalized (τ s (δ e ) = 0) assume here D VC (Γ,σ s ) is invertible Examples of such traces on C (Γ,σ) 1 tr Γ,σ ( a γ γ)=a e 2 on Γ = Γ 1 Γ 2,withΓ 1 perfect and σ = π 2 σ,forσ H 2 (Γ 2, U(1)), take any τ 1 tr Γ,σ Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
25 Projectively invariant operators What are eta and rho? Positive scalar curvature Lemma (Mathai) M spin, g R + (M). For s small enough, D VC (Γ,σ s ) is invertible Definition: Let M be spin, g R + (M). Callρ c τ s (D/) the direct limit of s ρ c τ s (D/), s U ρ c τ s lim 0 U Maps(U C) Theorem: bordism invariance of ρ c τ s If (M, g 0 )and(m, g 1 ) are Γ-cobordant in R + (M), then ρ c τ (D/ g0 )=ρ c τ (D/ g1 ) Proof: immediate, applying a C -algebraic Atiyah Patodi Singer index theorem, and the Lemma. Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
26 Projectively invariant operators What are eta and rho? Theorem (with C. Wahl 2013) M closed spin, connected, π 1 (M) =Γ 1 Γ 2, dim M =4k +1 Γ 1 has torsion N, π 1 (N) =Γ 2 s.t. N Â(N) f N c 0, c H 2 (BΓ 2, Q) If R + (M) then {g j } j N R + (M) non cobordant ρ c τ s (D/ gi ) ρ c τ s (D/ gj ). Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
27 Projectively invariant operators What are eta and rho? Theorem (with C. Wahl 2013) M closed spin, connected, π 1 (M) =Γ 1 Γ 2, dim M =4k +1 Γ 1 has torsion N, π 1 (N) =Γ 2 s.t. N Â(N) f N c 0, c H 2 (BΓ 2, Q) If R + (M) then {g j } j N R + (M) non cobordant ρ c τ s (D/ gi ) ρ c τ s (D/ gj ). Idea of the proof (after Botvinnik Gilkey, Piazza Schick, Piazza Leichtnam): Start with g 0 R + (M). Apply a machine to generate new non-cobordant metrics on M: a) Bordism theorem (by Gromov Lawson, Rosenberg Stolz, Botvinnik Gilkey) b) X 4k+1 closed spin, π 1(X )=Γ, ρ c τ s (D/ X ) 0, j [X ]=0 Ω spin,+ k (BΓ) Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
28 The machine: Projectively invariant operators What are eta and rho? a) Bordism theorem (Gromov Lawson): M, N spin Γ-cobordant manifold, M connected. If g R + (M), then G R + (W ) (of product structure near the boundary) b) Basic case: Γ = Z n (Botvinnik Gilkey): dim M = 7. There exists N 1 = S 7 /Z n lens space, g N1 R(N 1 ), and ρ Γ (D/ N1,g N1 ) 0. Moreover: Ω spin,+ k (BZ n )isfinite j [N 1 ]=0 Ω spin,+ k (BΓ) (here it is pure bordism, no PSC!) then k: ρ Γ (M, g k )=ρ Γ ((M, g 0 ) k(jn 1, g N1 )) = ρ Γ (M, g 0 )+kjρ Γ (N 1, g N1 ) ρ Γ (M, g k ) ρ Γ (M, g h ) k, h. Sara Azzali (Potsdam) Secondary invariants for two-cocycle twists Villa Mondragone, June 17, / 15
Invariants from noncommutative index theory for homotopy equivalences
Invariants from noncommutative index theory for homotopy equivalences Charlotte Wahl ECOAS 2010 Charlotte Wahl (Hannover) Invariants for homotopy equivalences ECOAS 2010 1 / 12 Basics in noncommutative
More informationK-Homology, Assembly and Rigidity Theorems for Relative Eta Invariants
K-Homology, Assembly and Rigidity Theorems for Relative Eta Invariants Department of Mathematics Pennsylvania State University Potsdam, May 16, 2008 Outline K-homology, elliptic operators and C*-algebras.
More informationThe topology of positive scalar curvature ICM Section Topology Seoul, August 2014
The topology of positive scalar curvature ICM Section Topology Seoul, August 2014 Thomas Schick Georg-August-Universität Göttingen ICM Seoul, August 2014 All pictures from wikimedia. Scalar curvature My
More informationTopology of the space of metrics with positive scalar curvature
Topology of the space of metrics with positive scalar curvature Boris Botvinnik University of Oregon, USA November 11, 2015 Geometric Analysis in Geometry and Topology, 2015 Tokyo University of Science
More informationGroups with torsion, bordism and rho-invariants
Groups with torsion, bordism and rho-invariants Paolo Piazza and Thomas Schick September 26, 2006 Abstract Let Γ be a discrete group, and let M be a closed spin manifold of dimension m > 3 with π 1(M)
More informationStratified surgery and the signature operator
Stratified surgery and the signature operator Paolo Piazza (Sapienza Università di Roma). Index Theory and Singular structures. Toulouse, June 1st 2017. Based on joint work with Pierre Albin (and also
More informationPositive scalar curvature, higher rho invariants and localization algebras
Positive scalar curvature, higher rho invariants and localization algebras Zhizhang Xie and Guoliang Yu Department of Mathematics, Texas A&M University Abstract In this paper, we use localization algebras
More informationThe eta invariant and the equivariant spin. bordism of spherical space form 2 groups. Peter B Gilkey and Boris Botvinnik
The eta invariant and the equivariant spin bordism of spherical space form 2 groups Peter B Gilkey and Boris Botvinnik Mathematics Department, University of Oregon Eugene Oregon 97403 USA Abstract We use
More informationThe kernel of the Dirac operator
The kernel of the Dirac operator B. Ammann 1 M. Dahl 2 E. Humbert 3 1 Universität Regensburg Germany 2 Institutionen för Matematik Kungliga Tekniska Högskolan, Stockholm Sweden 3 Laboratoire de Mathématiques
More informationarxiv: v4 [math.dg] 26 Jun 2018
POSITIVE SCALAR CURVATURE METRICS VIA END-PERIODIC MANIFOLDS MICHAEL HALLAM AND VARGHESE MATHAI arxiv:1706.09354v4 [math.dg] 26 Jun 2018 Abstract. We obtain two types of results on positive scalar curvature
More informationInvariance Theory, the Heat Equation, and the Atiyah-Singer Index Theorem
PETER B. GILKEY Department of Mathematics, University of Oregon Invariance Theory, the Heat Equation, and the Atiyah-Singer Index Theorem Second Edition CRC PRESS Boca Raton Ann Arbor London Tokyo Contents
More informationOn Invariants of Hirzebruch and Cheeger Gromov
ISSN 364-0380 (on line) 465-3060 (printed) 3 eometry & Topology Volume 7 (2003) 3 39 Published: 7 May 2003 On Invariants of Hirzebruch and Cheeger romov Stanley Chang Shmuel Weinberger Department of Mathematics,
More informationIndex theory on manifolds with corners: Generalized Gauss-Bonnet formulas
Index theory on singular manifolds I p. 1/4 Index theory on singular manifolds I Index theory on manifolds with corners: Generalized Gauss-Bonnet formulas Paul Loya Index theory on singular manifolds I
More informationRecent Progress on the Gromov-Lawson Conjecture
Recent Progress on the Gromov-Lawson Conjecture Jonathan Rosenberg (University of Maryland) in part joint work with Boris Botvinnik (University of Oregon) Stephan Stolz (University of Notre Dame) June
More informationTHE STRONG NOVIKOV CONJECTURE FOR LOW DEGREE COHOMOLOGY
THE STRONG NOVIKOV CONJECTURE FOR LOW DEGREE COHOMOLOGY BERNHARD HANKE AND THOMAS SCHICK ABSTRACT. We show that for each discrete group Γ, the rational assembly map K (BΓ Q K (C maxγ Q is injective on
More informationInvertible Dirac operators and handle attachments
Invertible Dirac operators and handle attachments Nadine Große Universität Leipzig (joint work with Mattias Dahl) Rauischholzhausen, 03.07.2012 Motivation Not every closed manifold admits a metric of positive
More informationHigher rho invariants and the moduli space of positive scalar curvature metrics
Higher rho invariants and the moduli space of positive scalar curvature metrics Zhizhang Xie 1 and Guoliang Yu 1,2 1 Department of Mathematics, Texas A&M University 2 Shanghai Center for Mathematical Sciences
More informationOn Higher Eta-Invariants and Metrics of Positive Scalar Curvature
K-Theory 24: 341 359, 2001. c 2001 Kluwer Academic Publishers. Printed in the Netherlands. 341 On Higher Eta-Invariants and Metrics of Positive Scalar Curvature ERIC LEICHTNAM 1, and PAOLO PIAZZA 2, 1
More informationModern index Theory lectures held at CIRM rencontré Theorie d indice, Mar 2006
Modern index Theory lectures held at CIRM rencontré Theorie d indice, Mar 2006 Thomas Schick, Göttingen Abstract Every elliptic (pseudo)-differential operator D on a closed manifold gives rise to a Fredholm
More informationUniversität Regensburg Mathematik
Universität Regensburg Mathematik Harmonic spinors and local deformations of the metric Bernd Ammann, Mattias Dahl, and Emmanuel Humbert Preprint Nr. 03/2010 HARMONIC SPINORS AND LOCAL DEFORMATIONS OF
More informationPeriodic-end Dirac Operators and Positive Scalar Curvature. Daniel Ruberman Nikolai Saveliev
Periodic-end Dirac Operators and Positive Scalar Curvature Daniel Ruberman Nikolai Saveliev 1 Recall from basic differential geometry: (X, g) Riemannian manifold Riemannian curvature tensor tr scalar curvature
More informationReal versus complex K-theory using Kasparov s bivariant KK
Real versus complex K-theory using Kasparov s bivariant KK Thomas Schick Last compiled November 17, 2003; last edited November 17, 2003 or later Abstract In this paper, we use the KK-theory of Kasparov
More informationFractional Index Theory
Fractional Index Theory Index a ( + ) = Z Â(Z ) Q Workshop on Geometry and Lie Groups The University of Hong Kong Institute of Mathematical Research 26 March 2011 Mathai Varghese School of Mathematical
More informationThe spectral action for Dirac operators with torsion
The spectral action for Dirac operators with torsion Christoph A. Stephan joint work with Florian Hanisch & Frank Pfäffle Institut für athematik Universität Potsdam Tours, ai 2011 1 Torsion Geometry, Einstein-Cartan-Theory
More informationA surgery formula for the smooth Yamabe invariant
A surgery formula for the smooth Yamabe invariant B. Ammann 1 M. Dahl 2 E. Humbert 3 1 Universität Regensburg Germany 2 Kungliga Tekniska Högskolan, Stockholm Sweden 3 Université Henri Poincaré, Nancy
More informationk=0 /D : S + S /D = K 1 2 (3.5) consistently with the relation (1.75) and the Riemann-Roch-Hirzebruch-Atiyah-Singer index formula
20 VASILY PESTUN 3. Lecture: Grothendieck-Riemann-Roch-Hirzebruch-Atiyah-Singer Index theorems 3.. Index for a holomorphic vector bundle. For a holomorphic vector bundle E over a complex variety of dim
More informationWEDNESDAY SEMINAR SUMMER 2017 INDEX THEORY
WEDNESDAY SEMINAR SUMMER 2017 INDEX THEORY The Atiyah-Singer index theorem is certainly one of the most influential collection of results from the last century. The theorem itself relates an analytic invariant,
More informationThe transverse index problem for Riemannian foliations
The transverse index problem for Riemannian foliations John Lott UC-Berkeley http://math.berkeley.edu/ lott May 27, 2013 The transverse index problem for Riemannian foliations Introduction Riemannian foliations
More informationFixed Point Theorem and Character Formula
Fixed Point Theorem and Character Formula Hang Wang University of Adelaide Index Theory and Singular Structures Institut de Mathématiques de Toulouse 29 May, 2017 Outline Aim: Study representation theory
More informationthe gromov-lawson-rosenberg conjecture 375 M. In particular, the kernel of D(M) is a Z=2-graded module over C`n. The element represented by ker D(M) i
j. differential geometry 45 (1997) 374-405 THE GROMOV-LAWSON-ROSENBERG CONJECTURE FOR GROUPS WITH PERIODIC COHOMOLOGY BORIS BOTVINNIK, PETER GILKEY & STEPHAN STOLZ 1. Introduction By a well-known result
More informationSPECTRAL ASYMMETRY AND RIEMANNIAN GEOMETRY
SPECTRAL ASYMMETRY AND RIEMANNIAN GEOMETRY M. F. ATIYAH, V. K. PATODI AND I. M. SINGER 1 Main Theorems If A is a positive self-adjoint elliptic (linear) differential operator on a compact manifold then
More informationDirac operators with torsion
Dirac operators with torsion Prof.Dr. habil. Ilka Agricola Philipps-Universität Marburg Golden Sands / Bulgaria, September 2011 1 Relations between different objects on a Riemannian manifold (M n, g):
More informationManifolds with complete metrics of positive scalar curvature
Manifolds with complete metrics of positive scalar curvature Shmuel Weinberger Joint work with Stanley Chang and Guoliang Yu May 5 14, 2008 Classical background. Fact If S p is the scalar curvature at
More informationOn the Twisted KK-Theory and Positive Scalar Curvature Problem
International Journal of Advances in Mathematics Volume 2017, Number 3, Pages 9-15, 2017 eissn 2456-6098 c adv-math.com On the Twisted KK-Theory and Positive Scalar Curvature Problem Do Ngoc Diep Institute
More informationOperator algebras and topology
Operator algebras and topology Thomas Schick 1 Last compiled November 29, 2001; last edited November 29, 2001 or later 1 e-mail: schick@uni-math.gwdg.de www: http://uni-math.gwdg.de/schick Fax: ++49-251/83
More informationA users guide to K-theory
A users guide to K-theory K-theory Alexander Kahle alexander.kahle@rub.de Mathematics Department, Ruhr-Universtät Bochum Bonn-Cologne Intensive Week: Tools of Topology for Quantum Matter, July 2014 Outline
More informationResearch Article The K-Theoretic Formulation of D-Brane Aharonov-Bohm Phases
Advances in High Energy Physics Volume 2012, Article ID 920486, 10 pages doi:10.1155/2012/920486 Research Article The K-Theoretic Formulation of D-Brane Aharonov-Bohm Phases Aaron R. Warren Department
More informationR/Z Index Theory. John Lott Department of Mathematics University of Michigan Ann Arbor, MI USA
Index Theory John Lott Department of Mathematics University of Michigan Ann Arbor, MI 48109-1003 USA lott@math.lsa.umich.edu Abstract We define topological and analytic indices in K-theory and show that
More informationThe strong Novikov conjecture for low degree cohomology
Geom Dedicata (2008 135:119 127 DOI 10.1007/s10711-008-9266-9 ORIGINAL PAPER The strong Novikov conjecture for low degree cohomology Bernhard Hanke Thomas Schick Received: 25 October 2007 / Accepted: 29
More informationIntroduction to Index Theory. Elmar Schrohe Institut für Analysis
Introduction to Index Theory Elmar Schrohe Institut für Analysis Basics Background In analysis and pde, you want to solve equations. In good cases: Linearize, end up with Au = f, where A L(E, F ) is a
More informationQuantising noncompact Spin c -manifolds
Quantising noncompact Spin c -manifolds Peter Hochs University of Adelaide Workshop on Positive Curvature and Index Theory National University of Singapore, 20 November 2014 Peter Hochs (UoA) Noncompact
More informationarxiv:math/ v3 [math.dg] 6 May 2001
arxiv:math/0010309v3 [math.dg] 6 ay 2001 ON POSITIVITY OF THE KADISON CONSTANT AND NONCOUTATIVE BLOCH THEORY VARGHESE ATHAI Abstract. In [V. athai, K-theory of twisted group C -algebras and positive scalar
More informationA surgery formula for the smooth Yamabe invariant
A surgery formula for the smooth Yamabe invariant B. Ammann 1 M. Dahl 2 E. Humbert 3 1 Universität Regensburg Germany 2 Kungliga Tekniska Högskolan, Stockholm Sweden 3 Université Henri Poincaré, Nancy
More informationOverview of Atiyah-Singer Index Theory
Overview of Atiyah-Singer Index Theory Nikolai Nowaczyk December 4, 2014 Abstract. The aim of this text is to give an overview of the Index Theorems by Atiyah and Singer. Our primary motivation is to understand
More informationRELATIVE INDEX PAIRING AND ODD INDEX THEOREM FOR EVEN DIMENSIONAL MANIFOLDS
RELATIVE INDEX PAIRING AND ODD INDEX THEORE FOR EVEN DIENSIONAL ANIFOLDS ZHIZHANG XIE Abstract. We prove an analogue for even dimensional manifolds of the Atiyah- Patodi-Singer twisted index theorem for
More informationFRACTIONAL ANALYTIC INDEX
FRACTIONAL ANALYTIC INDEX V. MATHAI, R.B. MELROSE, AND I.M. SINGER 1.2D; Revised: 28-1-2004; Run: February 3, 2004 Abstract. For a finite rank projective bundle over a compact manifold, so associated to
More informationAn Introduction to the Dirac Operator in Riemannian Geometry. S. Montiel. Universidad de Granada
An Introduction to the Dirac Operator in Riemannian Geometry S. Montiel Universidad de Granada Varna, June 2007 1 Genealogy of the Dirac Operator 1913 É. Cartan Orthogonal Lie algebras 1927 W. Pauli Inner
More informationA surgery formula for the (smooth) Yamabe invariant
A surgery formula for the (smooth) Yamabe invariant B. Ammann 1 M. Dahl 2 E. Humbert 3 1 Universität Regensburg Germany 2 Kungliga Tekniska Högskolan, Stockholm Sweden 3 Université Henri Poincaré, Nancy
More informationApproximating L 2 -signatures by their compact analogues
Approximating L 2 -signatures by their compact analogues Wolfgang Lück Fachbereich Mathematik Universität Münster Einsteinstr. 62 4849 Münster Thomas Schick Fakultät für Mathematik Universität Göttingen
More informationQuantising proper actions on Spin c -manifolds
Quantising proper actions on Spin c -manifolds Peter Hochs University of Adelaide Differential geometry seminar Adelaide, 31 July 2015 Joint work with Mathai Varghese (symplectic case) Geometric quantization
More informationThe Yamabe invariant and surgery
The Yamabe invariant and surgery B. Ammann 1 M. Dahl 2 E. Humbert 3 1 Universität Regensburg Germany 2 Kungliga Tekniska Högskolan, Stockholm Sweden 3 Université François-Rabelais, Tours France Geometric
More informationREFINED ANALYTIC TORSION. Abstract
REFINED ANALYTIC TORSION Maxim Braverman & Thomas Kappeler Abstract Given an acyclic representation α of the fundamental group of a compact oriented odd-dimensional manifold, which is close enough to an
More informationLie groupoids, cyclic homology and index theory
Lie groupoids, cyclic homology and index theory (Based on joint work with M. Pflaum and X. Tang) H. Posthuma University of Amsterdam Kyoto, December 18, 2013 H. Posthuma (University of Amsterdam) Lie groupoids
More informationEta Invariant and Conformal Cobordism
Annals of Global Analysis and Geometry 27: 333 340 (2005) C 2005 Springer. 333 Eta Invariant and Conformal Cobordism XIANZHE DAI Department of Mathematics, University of California, Santa Barbara, California
More informationThe spectral zeta function
The spectral zeta function Bernd Ammann June 4, 215 Abstract In this talk we introduce spectral zeta functions. The spectral zeta function of the Laplace-Beltrami operator was already introduced by Minakshisundaram
More informationSpectral applications of metric surgeries
Spectral applications of metric surgeries Pierre Jammes Neuchâtel, june 2013 Introduction and motivations Examples of applications of metric surgeries Let (M n, g) be a closed riemannian manifold, and
More informationApproximating L 2 -signatures by their compact analogues
Approximating L 2 -signatures by their compact analogues Wolfgang Lück Fachbereich Mathematik Universität Münster Einsteinstr. 62 4849 Münster Thomas Schick Fakultät für Mathematik Universität Göttingen
More informationAtiyah-Singer Revisited
Atiyah-Singer Revisited Paul Baum Penn State Texas A&M Universty College Station, Texas, USA April 1, 2014 From E 1, E 2,..., E n obtain : 1) The Dirac operator of R n D = n j=1 E j x j 2) The Bott generator
More informationExpanders and Morita-compatible exact crossed products
Expanders and Morita-compatible exact crossed products Paul Baum Penn State Joint Mathematics Meetings R. Kadison Special Session San Antonio, Texas January 10, 2015 EXPANDERS AND MORITA-COMPATIBLE EXACT
More informationMathematisches Forschungsinstitut Oberwolfach. Analysis, Geometry and Topology of Positive Scalar Curvature Metrics
Mathematisches Forschungsinstitut Oberwolfach Report No. 36/2014 DOI: 10.4171/OWR/2014/36 Analysis, Geometry and Topology of Positive Scalar Curvature Metrics Organised by Bernd Ammann, Regensburg Bernhard
More information10:30-12:00 (1) Elliptic Cohomology and Conformal Field Theories: An Introduction. (Prof. G. Laures) Example: Heat operator, Laplace operator.
Winter School From Field Theories to Elliptic Objects Schloss Mickeln, February 28 March 4, 2006 Graduiertenkolleg 1150: Homotopy and Cohomology Prof. Dr. G. Laures, Universität Bochum Dr. E. Markert,
More informationWHAT IS K-HOMOLOGY? Paul Baum Penn State. Texas A&M University College Station, Texas, USA. April 2, 2014
WHAT IS K-HOMOLOGY? Paul Baum Penn State Texas A&M University College Station, Texas, USA April 2, 2014 Paul Baum (Penn State) WHAT IS K-HOMOLOGY? April 2, 2014 1 / 56 Let X be a compact C manifold without
More informationBEYOND ELLIPTICITY. Paul Baum Penn State. Fields Institute Toronto, Canada. June 20, 2013
BEYOND ELLIPTICITY Paul Baum Penn State Fields Institute Toronto, Canada June 20, 2013 Paul Baum (Penn State) Beyond Ellipticity June 20, 2013 1 / 47 Minicourse of five lectures: 1. Dirac operator 2. Atiyah-Singer
More informationMathematische Annalen
Math. Ann. 316, 617 657 2000) c Springer-Verlag 2000 Mathematische Annalen Signatures and higher signatures of S 1 -quotients John Lott Received: 13 January 1999 Abstract. We define and study the signature,
More informationIntroduction to the Baum-Connes conjecture
Introduction to the Baum-Connes conjecture Nigel Higson, John Roe PSU NCGOA07 Nigel Higson, John Roe (PSU) Introduction to the Baum-Connes conjecture NCGOA07 1 / 15 History of the BC conjecture Lecture
More informationBURGHELEA-FRIEDLANDER-KAPPELER S GLUING FORMULA AND ITS APPLICATIONS TO THE ZETA-DETERMINANTS OF DIRAC LAPLACIANS
Trends in Mathematics Information Center for Mathematical Sciences Volume 7, Number 1,June 004, Pages 103 113 BURGHELEA-FRIEDLANDER-KAPPELER S GLUING FORMULA AND ITS APPLICATIONS TO THE ZETA-DETERMINANTS
More informationarxiv:math/ v3 [math.dg] 7 Dec 2004
FRACTIONAL ANALYTIC INDEX arxiv:math/0402329v3 [math.dg] 7 Dec 2004 V. MATHAI, R.B. MELROSE, AND I.M. SINGER 1.2J; Revised: 5-12-2004; Run: February 19, 2008 Abstract. For a finite rank projective bundle
More informationA surgery formula for the (smooth) Yamabe invariant
A surgery formula for the (smooth) Yamabe invariant B. Ammann 1 M. Dahl 2 E. Humbert 3 1 Universität Regensburg Germany 2 Kungliga Tekniska Högskolan, Stockholm Sweden 3 Université Henri Poincaré, Nancy
More informationKR-theory. Jean-Louis Tu. Lyon, septembre Université de Lorraine France. IECL, UMR 7502 du CNRS
Jean-Louis Tu Université de Lorraine France Lyon, 11-13 septembre 2013 Complex K -theory Basic definition Definition Let M be a compact manifold. K (M) = {[E] [F] E, F vector bundles } [E] [F] [E ] [F
More informationTHE MCKEAN-SINGER FORMULA VIA EQUIVARIANT QUANTIZATION
THE MCKEAN-SINGER FORMULA VIA EQUIVARIANT QUANTIZATION EUGENE RABINOVICH 1. Introduction The aim of this talk is to present a proof, using the language of factorization algebras, and in particular the
More informationTraces and Determinants of
Traces and Determinants of Pseudodifferential Operators Simon Scott King's College London OXFORD UNIVERSITY PRESS CONTENTS INTRODUCTION 1 1 Traces 7 1.1 Definition and uniqueness of a trace 7 1.1.1 Traces
More informationTHE SYMMETRY OF spin C DIRAC SPECTRUMS ON RIEMANNIAN PRODUCT MANIFOLDS
J. Korean Math. Soc. 52 (2015), No. 5, pp. 1037 1049 http://dx.doi.org/10.4134/jkms.2015.52.5.1037 THE SYMMETRY OF spin C DIRAC SPECTRUMS ON RIEMANNIAN PRODUCT MANIFOLDS Kyusik Hong and Chanyoung Sung
More informationTopological rigidity for non-aspherical manifolds by M. Kreck and W. Lück
Topological rigidity for non-aspherical manifolds by M. Kreck and W. Lück July 11, 2006 Abstract The Borel Conjecture predicts that closed aspherical manifolds are topological rigid. We want to investigate
More informationReconstruction theorems in noncommutative Riemannian geometry
Reconstruction theorems in noncommutative Riemannian geometry Department of Mathematics California Institute of Technology West Coast Operator Algebra Seminar 2012 October 21, 2012 References Published
More informationEigenvalue estimates for Dirac operators with torsion II
Eigenvalue estimates for Dirac operators with torsion II Prof.Dr. habil. Ilka Agricola Philipps-Universität Marburg Metz, March 2012 1 Relations between different objects on a Riemannian manifold (M n,
More informationIndex Theory and the Baum-Connes conjecture
Index Theory and the Baum-Connes conjecture Thomas Schick Mathematisches Institut Georg-August-Universität Göttingen These notes are based on lectures on index theory, topology, and operator algebras at
More informationBFK-gluing formula for zeta-determinants of Laplacians and a warped product metric
BFK-gluing formula for zeta-determinants of Laplacians and a warped product metric Yoonweon Lee (Inha University, Korea) Geometric and Singular Analysis Potsdam University February 20-24, 2017 (Joint work
More informationC*-Algebraic Higher Signatures and an Invariance Theorem in Codimension Two
C*-Algebraic Higher Signatures and an Invariance Theorem in Codimension Two Nigel Higson, Thomas Schick, and Zhizhang Xie Abstract We revisit the construction of signature classes in C -algebra K-theory,
More informationEQUIVARIANT AND FRACTIONAL INDEX OF PROJECTIVE ELLIPTIC OPERATORS. V. Mathai, R.B. Melrose & I.M. Singer. Abstract
j. differential geometry x78 (2008) 465-473 EQUIVARIANT AND FRACTIONAL INDEX OF PROJECTIVE ELLIPTIC OPERATORS V. Mathai, R.B. Melrose & I.M. Singer Abstract In this note the fractional analytic index,
More informationCortona Analysis and Topology in interaction. Abstracts for Monday June 26th
Cortona 2017 Analysis and Topology in interaction Abstracts for Monday June 26th Peter Teichner (Max Plank Institute, Bonn and University of California at Berkeley) Super geometric interpretations of equivariant
More informationENLARGEABILITY AND INDEX THEORY. B. Hanke and T. Schick. Abstract
ENLARGEABILITY AND INDEX THEORY B. Hanke and T. Schick Abstract Let M be a closed enlargeable spin manifold. We show nontriviality of the universal index obstruction in the K-theory of the maximal C -algebra
More informationSpectral Triples on the Sierpinski Gasket
Spectral Triples on the Sierpinski Gasket Fabio Cipriani Dipartimento di Matematica Politecnico di Milano - Italy ( Joint works with D. Guido, T. Isola, J.-L. Sauvageot ) AMS Meeting "Analysis, Probability
More informationc Birkhäuser Verlag, Basel 1998 GAFA Geometric And Functional Analysis
GAFA, Geom. funct. anal. Vol. 8 (1998) 17 58 1016-443X/98/010017-42 $ 1.50+0.20/0 c Birkhäuser Verlag, Basel 1998 GAFA Geometric And Functional Analysis SPECTRAL SECTIONS AND HIGHER ATIYAH-PATODI-SINGER
More informationNoncommutative Geometry Lecture 3: Cyclic Cohomology
Noncommutative Geometry Lecture 3: Cyclic Cohomology Raphaël Ponge Seoul National University October 25, 2011 1 / 21 Hochschild Cohomology Setup A is a unital algebra over C. Definition (Hochschild Complex)
More informationREFINED ANALYTIC TORSION. Maxim Braverman & Thomas Kappeler. Abstract
j. differential geometry 78 2008) 193-267 REFINED ANALYTIC TORSION Maxim Braverman & Thomas Kappeler Abstract Given an acyclic representation α of the fundamental group of a compact oriented odd-dimensional
More informationAn Introduction to the Stolz-Teichner Program
Intro to STP 1/ 48 Field An Introduction to the Stolz-Teichner Program Australian National University October 20, 2012 Outline of Talk Field Smooth and Intro to STP 2/ 48 Field Field Motivating Principles
More informationThe Dirac-Ramond operator and vertex algebras
The Dirac-Ramond operator and vertex algebras Westfälische Wilhelms-Universität Münster cvoigt@math.uni-muenster.de http://wwwmath.uni-muenster.de/reine/u/cvoigt/ Vanderbilt May 11, 2011 Kasparov theory
More informationAdvanced Course: Transversal Dirac operators on distributions, foliations, and G-manifolds. Ken Richardson and coauthors
Advanced Course: Transversal Dirac operators on distributions, foliations, and G-manifolds Ken Richardson and coauthors Universitat Autònoma de Barcelona May 3-7, 2010 Universitat Autònoma de Barcelona
More informationInfinitesimal Einstein Deformations. Kähler Manifolds
on Nearly Kähler Manifolds (joint work with P.-A. Nagy and U. Semmelmann) Gemeinsame Jahrestagung DMV GDM Berlin, March 30, 2007 Nearly Kähler manifolds Definition and first properties Examples of NK manifolds
More informationCelebrating One Hundred Fifty Years of. Topology. ARBEITSTAGUNG Bonn, May 22, 2013
Celebrating One Hundred Fifty Years of Topology John Milnor Institute for Mathematical Sciences Stony Brook University (www.math.sunysb.edu) ARBEITSTAGUNG Bonn, May 22, 2013 Algebra & Number Theory 3 4
More informationON UNIFORM K-HOMOLOGY OUTLINE. Ján Špakula. Oberseminar C*-algebren. Definitions C*-algebras. Review Coarse assembly
ON UNIFORM K-HOMOLOGY Ján Špakula Uni Münster Oberseminar C*-algebren Nov 25, 2008 Ján Špakula ( Uni Münster ) On uniform K-homology Nov 25, 2008 1 / 27 OUTLINE 1 INTRODUCTION 2 COARSE GEOMETRY Definitions
More informationPOSITIVE SCALAR CURVATURE FOR MANIFOLDS WITH ELEMENTARY ABELIAN FUNDAMENTAL GROUP
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY Volume 00, Number 0, Pages 000 000 S 0002-9939(XX)0000-0 POSITIVE SCALAR CURVATURE FOR MANIFOLDS WITH ELEMENTARY ABELIAN FUNDAMENTAL GROUP BORIS BOTVINNIK
More informationTHE SPACE OF POSITIVE SCALAR CURVATURE METRICS ON A MANIFOLD WITH BOUNDARY
THE SPACE OF POSITIVE SCALAR CURVATURE METRICS ON A MANIFOLD WITH BOUNDARY MARK WALSH Abstract. We study the space of Riemannian metrics with positive scalar curvature on a compact manifold with boundary.
More informationTransverse geometry. consisting of finite sums of monomials of the form
Transverse geometry The space of leaves of a foliation (V, F) can be described in terms of (M, Γ), with M = complete transversal and Γ = holonomy pseudogroup. The natural transverse coordinates form the
More informationRemarks on Chern-Simons Theory. Dan Freed University of Texas at Austin
Remarks on Chern-Simons Theory Dan Freed University of Texas at Austin 1 MSRI: 1982 2 Classical Chern-Simons 3 Quantum Chern-Simons Witten (1989): Integrate over space of connections obtain a topological
More informationTRANSVERSAL DIRAC OPERATORS ON DISTRIBUTIONS, FOLIATIONS, AND G-MANIFOLDS LECTURE NOTES
TRANSVERSAL DIRAC OPERATORS ON DISTRIBUTIONS, FOLIATIONS, AND G-MANIFOLDS LECTURE NOTES KEN RICHARDSON Abstract. In these lectures, we investigate generalizations of the ordinary Dirac operator to manifolds
More informationNONNEGATIVE CURVATURE AND COBORDISM TYPE. 1. Introduction
NONNEGATIVE CURVATURE AND COBORDISM TYPE ANAND DESSAI AND WILDERICH TUSCHMANN Abstract. We show that in each dimension n = 4k, k 2, there exist infinite sequences of closed simply connected Riemannian
More informationIndex Theory and Spin Geometry
Index Theory and Spin Geometry Fabian Lenhardt and Lennart Meier March 20, 2010 Many of the familiar (and not-so-familiar) invariants in the algebraic topology of manifolds may be phrased as an index of
More informationDirac Operator. Göttingen Mathematical Institute. Paul Baum Penn State 6 February, 2017
Dirac Operator Göttingen Mathematical Institute Paul Baum Penn State 6 February, 2017 Five lectures: 1. Dirac operator 2. Atiyah-Singer revisited 3. What is K-homology? 4. The Riemann-Roch theorem 5. K-theory
More informationGeometric Structures in Mathematical Physics Non-existence of almost complex structures on quaternion-kähler manifolds of positive type
Geometric Structures in Mathematical Physics Non-existence of almost complex structures on quaternion-kähler manifolds of positive type Paul Gauduchon Golden Sands, Bulgaria September, 19 26, 2011 1 Joint
More information