Spinc,Mpc and Symplectic Dirac Operators
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Density of Thin Film Billiard Reflection Pseudogroup in Hamiltonian Symplectomorphism Pseudogroup Alexey Glutsyuk
Density of thin film billiard reflection pseudogroup in Hamiltonian symplectomorphism pseudogroup Alexey Glutsyuk To cite this version: Alexey Glutsyuk. Density of thin film billiard reflection pseudogroup in Hamiltonian symplectomor- phism pseudogroup. 2020. hal-03026432v2 HAL Id: hal-03026432 https://hal.archives-ouvertes.fr/hal-03026432v2 Preprint submitted on 6 Dec 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Density of thin film billiard reflection pseudogroup in Hamiltonian symplectomorphism pseudogroup Alexey Glutsyuk∗yzx December 3, 2020 Abstract Reflections from hypersurfaces act by symplectomorphisms on the space of oriented lines with respect to the canonical symplectic form. We consider an arbitrary C1-smooth hypersurface γ ⊂ Rn+1 that is either a global strictly convex closed hypersurface, or a germ of hy- persurface. We deal with the pseudogroup generated by compositional ratios of reflections from γ and of reflections from its small deforma- tions. In the case, when γ is a global convex hypersurface, we show that the latter pseudogroup is dense in the pseudogroup of Hamiltonian diffeomorphisms between subdomains of the phase cylinder: the space of oriented lines intersecting γ transversally. We prove an analogous local result in the case, when γ is a germ. -
Symplectic Structures on Gauge Theory?
Commun. Math. Phys. 193, 47 – 67 (1998) Communications in Mathematical Physics c Springer-Verlag 1998 Symplectic Structures on Gauge Theory? Nai-Chung Conan Leung School of Mathematics, 127 Vincent Hall, University of Minnesota, Minneapolis, MN 55455, USA Received: 27 February 1996 / Accepted: 7 July 1997 [ ] Abstract: We study certain natural differential forms ∗ and their equivariant ex- tensions on the space of connections. These forms are defined usingG the family local index theorem. When the base manifold is symplectic, they define a family of sym- plectic forms on the space of connections. We will explain their relationships with the Einstein metric and the stability of vector bundles. These forms also determine primary and secondary characteristic forms (and their higher level generalizations). Contents 1 Introduction ............................................... 47 2 Higher Index of the Universal Family ........................... 49 2.1 Dirac operators ............................................. 50 2.2 ∂-operator ................................................ 52 3 Moment Map and Stable Bundles .............................. 53 4 Space of Generalized Connections ............................. 58 5 Higer Level Chern–Simons Forms ............................. 60 [ ] 6 Equivariant Extensions of ∗ ................................ 63 1. Introduction In this paper, we study natural differential forms [2k] on the space of connections on a vector bundle E over X, A i [2k] FA (A)(B1,B2,...,B2 )= Tr[e 2π B1B2 B2 ] Aˆ(X). k ··· k sym ZX They are invariant closed differential forms on . They are introduced as the family local indexG for universal family of operators. A ? This research is supported by NSF grant number: DMS-9114456 48 N-C. C. Leung We use them to define higher Chern-Simons forms of E: [ ] ch(E; A0,...,A )=∗ L(A0,...,A ), l l ◦ l l and discuss their properties. -
Lecture 1: Basic Concepts, Problems, and Examples
LECTURE 1: BASIC CONCEPTS, PROBLEMS, AND EXAMPLES WEIMIN CHEN, UMASS, SPRING 07 In this lecture we give a general introduction to the basic concepts and some of the fundamental problems in symplectic geometry/topology, where along the way various examples are also given for the purpose of illustration. We will often give statements without proofs, which means that their proof is either beyond the scope of this course or will be treated more systematically in later lectures. 1. Symplectic Manifolds Throughout we will assume that M is a C1-smooth manifold without boundary (unless specific mention is made to the contrary). Very often, M will also be closed (i.e., compact). Definition 1.1. A symplectic structure on a smooth manifold M is a 2-form ! 2 Ω2(M), which is (1) nondegenerate, and (2) closed (i.e. d! = 0). (Recall that a 2-form ! 2 Ω2(M) is said to be nondegenerate if for every point p 2 M, !(u; v) = 0 for all u 2 TpM implies v 2 TpM equals 0.) The pair (M; !) is called a symplectic manifold. Before we discuss examples of symplectic manifolds, we shall first derive some im- mediate consequences of a symplectic structure. (1) The nondegeneracy condition on ! is equivalent to the condition that M has an even dimension 2n and the top wedge product !n ≡ ! ^ ! · · · ^ ! is nowhere vanishing on M, i.e., !n is a volume form. In particular, M must be orientable, and is canonically oriented by !n. The nondegeneracy condition is also equivalent to the condition that M is almost complex, i.e., there exists an endomorphism J of TM such that J 2 = −Id. -
Ellipticity of the Symplectic Twistor Complex
ARCHIVUM MATHEMATICUM (BRNO) Tomus 47 (2011), 309–327 ELLIPTICITY OF THE SYMPLECTIC TWISTOR COMPLEX Svatopluk Krýsl Abstract. For a Fedosov manifold (symplectic manifold equipped with a symplectic torsion-free affine connection) admitting a metaplectic structure, we shall investigate two sequences of first order differential operators acting on sections of certain infinite rank vector bundles defined over this manifold. The differential operators are symplectic analogues of the twistor operators known from Riemannian or Lorentzian spin geometry. It is known that the mentioned sequences form complexes if the symplectic connection is of Ricci type. In this paper, we prove that certain parts of these complexes are elliptic. 1. Introduction In this article, we prove the ellipticity of certain parts of the so called symplectic twistor complexes. The symplectic twistor complexes are two sequences of first order differential operators defined over Ricci type Fedosov manifolds admitting a metaplectic structure. The mentioned parts of these complexes will be called truncated symplectic twistor complexes and will be defined later in this text. Now, let us say a few words about the Fedosov manifolds. Formally speaking, a Fedosov manifold is a triple (M 2l, ω, ∇) where (M 2l, ω) is a (for definiteness 2l dimensional) symplectic manifold and ∇ is a symplectic torsion-free affine connection. Connections satisfying these two properties are usually called Fedosov connections in honor of Boris Fedosov who used them to obtain a deformation quantization for symplectic manifolds. (See Fedosov [5].) Let us also mention that in contrary to torsion-free Levi-Civita connections, the Fedosov ones are not unique. We refer an interested reader to Tondeur [18] and Gelfand, Retakh, Shubin [6] for more information. -
Symplectic Topology Math 705 Notes by Patrick Lei, Spring 2020
Symplectic Topology Math 705 Notes by Patrick Lei, Spring 2020 Lectures by R. Inanç˙ Baykur University of Massachusetts Amherst Disclaimer These notes were taken during lecture using the vimtex package of the editor neovim. Any errors are mine and not the instructor’s. In addition, my notes are picture-free (but will include commutative diagrams) and are a mix of my mathematical style (omit lengthy computations, use category theory) and that of the instructor. If you find any errors, please contact me at [email protected]. Contents Contents • 2 1 January 21 • 5 1.1 Course Description • 5 1.2 Organization • 5 1.2.1 Notational conventions•5 1.3 Basic Notions • 5 1.4 Symplectic Linear Algebra • 6 2 January 23 • 8 2.1 More Basic Linear Algebra • 8 2.2 Compatible Complex Structures and Inner Products • 9 3 January 28 • 10 3.1 A Big Theorem • 10 3.2 More Compatibility • 11 4 January 30 • 13 4.1 Homework Exercises • 13 4.2 Subspaces of Symplectic Vector Spaces • 14 5 February 4 • 16 5.1 Linear Algebra, Conclusion • 16 5.2 Symplectic Vector Bundles • 16 6 February 6 • 18 6.1 Proof of Theorem 5.11 • 18 6.2 Vector Bundles, Continued • 18 6.3 Compatible Triples on Manifolds • 19 7 February 11 • 21 7.1 Obtaining Compatible Triples • 21 7.2 Complex Structures • 21 8 February 13 • 23 2 3 8.1 Kähler Forms Continued • 23 8.2 Some Algebraic Geometry • 24 8.3 Stein Manifolds • 25 9 February 20 • 26 9.1 Stein Manifolds Continued • 26 9.2 Topological Properties of Kähler Manifolds • 26 9.3 Complex and Symplectic Structures on 4-Manifolds • 27 10 February 25 -
Hamiltonian and Symplectic Symmetries: an Introduction
BULLETIN (New Series) OF THE AMERICAN MATHEMATICAL SOCIETY Volume 54, Number 3, July 2017, Pages 383–436 http://dx.doi.org/10.1090/bull/1572 Article electronically published on March 6, 2017 HAMILTONIAN AND SYMPLECTIC SYMMETRIES: AN INTRODUCTION ALVARO´ PELAYO In memory of Professor J.J. Duistermaat (1942–2010) Abstract. Classical mechanical systems are modeled by a symplectic mani- fold (M,ω), and their symmetries are encoded in the action of a Lie group G on M by diffeomorphisms which preserve ω. These actions, which are called sym- plectic, have been studied in the past forty years, following the works of Atiyah, Delzant, Duistermaat, Guillemin, Heckman, Kostant, Souriau, and Sternberg in the 1970s and 1980s on symplectic actions of compact Abelian Lie groups that are, in addition, of Hamiltonian type, i.e., they also satisfy Hamilton’s equations. Since then a number of connections with combinatorics, finite- dimensional integrable Hamiltonian systems, more general symplectic actions, and topology have flourished. In this paper we review classical and recent re- sults on Hamiltonian and non-Hamiltonian symplectic group actions roughly starting from the results of these authors. This paper also serves as a quick introduction to the basics of symplectic geometry. 1. Introduction Symplectic geometry is concerned with the study of a notion of signed area, rather than length, distance, or volume. It can be, as we will see, less intuitive than Euclidean or metric geometry and it is taking mathematicians many years to understand its intricacies (which is work in progress). The word “symplectic” goes back to the 1946 book [164] by Hermann Weyl (1885–1955) on classical groups. -
Complex of Twistor Operators in Symplectic Spin Geometry
Complex of twistor operators in symplectic spin geometry Svatopluk Kr´ysl ∗ Charles University of Prague, Sokolovsk´a83, Praha, Czech Republic. † October 22, 2018 Abstract For a symplectic manifold admitting a metaplectic structure (a symplectic ana- logue of the Riemannian spin structure), we construct a sequence consisting of differential operators using a symplectic torsion-free affine connection. All but one of these operators are of first order. The first order ones are symplectic analogues of the twistor operators known from Riemannian spin geometry. We prove that under the condition the symplectic Weyl curvature tensor field of the symplectic connection vanishes, the mentioned sequence forms a complex. This gives rise to a new complex for the so called Ricci type symplectic manifolds, which admit a metaplectic structure. Math. Subj. Class.: 53C07, 53D05, 58J10. Keywords: Fedosov manifolds, metaplectic structures, symplectic spinors, Kostant spinors, Segal-Shale-Weil representation, complexes of differential op- erators. 1 Introduction In the paper, we shall introduce a sequence of differential operators acting on symplectic spinor valued exterior differential forms over a symplectic manifold (M,ω) admitting the so called metaplectic structure. To define these operators, arXiv:0904.0763v1 [math.SG] 6 Apr 2009 we make use of a symplectic torsion-free affine connection on (M,ω). Under certain condition on the curvature of the connection , described∇ bellow, we prove that the mentioned sequence forms a complex. ∇ Let us say a few words about the metaplectic structure. The symplectic group Sp(2l, R) admits a non-trivial two-fold covering, the so called metaplectic group, which we shall denote by Mp(2l, R). -
SYMPLECTIC GEOMETRY Lecture Notes, University of Toronto
SYMPLECTIC GEOMETRY Eckhard Meinrenken Lecture Notes, University of Toronto These are lecture notes for two courses, taught at the University of Toronto in Spring 1998 and in Fall 2000. Our main sources have been the books “Symplectic Techniques” by Guillemin-Sternberg and “Introduction to Symplectic Topology” by McDuff-Salamon, and the paper “Stratified symplectic spaces and reduction”, Ann. of Math. 134 (1991) by Sjamaar-Lerman. Contents Chapter 1. Linear symplectic algebra 5 1. Symplectic vector spaces 5 2. Subspaces of a symplectic vector space 6 3. Symplectic bases 7 4. Compatible complex structures 7 5. The group Sp(E) of linear symplectomorphisms 9 6. Polar decomposition of symplectomorphisms 11 7. Maslov indices and the Lagrangian Grassmannian 12 8. The index of a Lagrangian triple 14 9. Linear Reduction 18 Chapter 2. Review of Differential Geometry 21 1. Vector fields 21 2. Differential forms 23 Chapter 3. Foundations of symplectic geometry 27 1. Definition of symplectic manifolds 27 2. Examples 27 3. Basic properties of symplectic manifolds 34 Chapter 4. Normal Form Theorems 43 1. Moser’s trick 43 2. Homotopy operators 44 3. Darboux-Weinstein theorems 45 Chapter 5. Lagrangian fibrations and action-angle variables 49 1. Lagrangian fibrations 49 2. Action-angle coordinates 53 3. Integrable systems 55 4. The spherical pendulum 56 Chapter 6. Symplectic group actions and moment maps 59 1. Background on Lie groups 59 2. Generating vector fields for group actions 60 3. Hamiltonian group actions 61 4. Examples of Hamiltonian G-spaces 63 3 4 CONTENTS 5. Symplectic Reduction 72 6. Normal forms and the Duistermaat-Heckman theorem 78 7. -
Symplectic Topology, Geometry and Gauge Theory Lisa Jeffrey
Symplectic Topology, Geometry and Gauge Theory Lisa Jeffrey 1 Symplectic geometry has its roots in classical mechanics. A prototype for a symplectic manifold is the phase space which parametrizes the position q and momentum p of a classical particle. If the Hamiltonian (kinetic + potential en- ergy) is p2 H = + V (q) 2 then the motion of the particle is described by Hamilton’s equations dq ∂H = = p dt ∂p dp ∂H ∂V = − = − dt ∂q ∂q 2 In mathematical terms, a symplectic manifold is a manifold M endowed with a 2-form ω which is: • closed: dω = 0 (integral of ω over a 2-dimensional subman- ifold which is the boundary of a 3-manifold is 0) • nondegenerate (at any x ∈ M ω gives a map ∗ from the tangent space TxM to its dual Tx M; nondegeneracy means this map is invertible) If M = R2 is the phase space equipped with the Hamiltonian H then the symplectic form ω = dq ∧ dp transforms the 1-form ∂H ∂H dH = dp + dq ∂p ∂q to the vector field ∂H ∂H X = (− , ) H ∂q ∂p 3 The flow associated to XH is the flow satisfying Hamilton’s equations. Darboux’s theorem says that near any point of M there are local coordinates x1, . , xn, y1, . , yn such that Xn ω = dxi ∧ dyi. i=1 (Note that symplectic structures only exist on even-dimensional manifolds) Thus there are no local invariants that distin- guish between symplectic structures: at a local level all symplectic forms are identical. In contrast, Riemannian metrics g have local invariants, the curvature tensors R(g), such that if R(g1) =6 R(g2) then there is no smooth map that pulls back g1 to g2. -
Holonomic D-Modules and Positive Characteristic
Japan. J. Math. 4, 1–25 (2009) DOI: 10.1007/s11537-009-0852-x Holonomic -modules and positive characteristic Maxim Kontsevich Received: 8 December 2008 / Revised: 6 January 2009 / Accepted: 11 February 2009 Published online: ????? c The Mathematical Society of Japan and Springer 2009 Communicated by: Toshiyuki Kobayashi Abstract. We discuss a hypothetical correspondence between holonomic -modules on an al- gebraic variety X defined over a field of zero characteristic, and certain families of Lagrangian subvarieties in the cotangent bundle to X. The correspondence is based on the reduction to posi- tive characteristic. Keywords and phrases: rings of differential operators and their modules, characteristic p methods Mathematics Subject Classification (2000): 13N10, 13A35 1. Quantization and -modules 1.1. Quantization Let us recall the heuristic dictionary of quantization. symplectic C∞-manifold (Y,ω) ←→ complex Hilbert space H complex-valued functions on Y ←→ operators in H Lagrangian submanifolds L ⊂ Y ←→ vectors v ∈ H In the basic example of the cotangent bundle Y = T ∗X the space H is L2(X), functions on Y which are polynomial along fibers of the projection Y = T ∗X → X correspond to differential operators, and with the Lagrangian manifold L ⊂ Y This article is based on the 5th Takagi Lectures that the author delivered at the University of Tokyo on October 4 and 5, 2008. M. KONTSEVICH Institut des Hautes Etudes´ Scientifiques, 35 route de Chartres, Bures-sur-Yvette 91440, France (e-mail: [email protected]) 2 M. Kontsevich of the form L = graphdF for some function F ∈ C∞(Y) we associate (approxi- mately) vector exp(iF/) where → 0 is a small parameter (“Planck constant”). -
Symplectic Differential Geometry Definition 1.1. a Two Form Ω on A
1. Lecture 2: Symplectic differential geometry Definition 1.1. A two form ! on a manifold M is symplectic if and only if 1) 8x 2 M, !(x) is symplectic on TxM; 2) d! = 0 (! is closed). Examples: 1) (R2n; σ) is symplectic manifold. 2) If N is a manifold, then ∗ T N = f(q; p)jp linear form on TxMg is a symplectic manifold. Let q1; ··· ; qn be local coordinates on N and let p1; ··· ; pn be the dual coordinates. Then the symplectic form is defined by n X i ! = dp ^ dqi: i=1 One can check that ! does not depend on the choice of coordinates and is a symplectic form. We can also define a one form n X i λ = pdq = p dqi: i=1 It is well defined and dλ = !. 3) Projective algebraic manifolds(See also K¨ahlermanifolds) CP n has a canonical symplectic structure σ and is also a complex manifold. The complex structure J and the symplectic form σ are compatible. CP n has a hermitian metric h. For any z 2 CP n, h(z) n is a hermitian inner product on TzCP . h = g + iσ, where g is a Riemannian metric and σ(Jξ; ξ) = g(ξ; ξ). Claim: A complex submanifold M of CP n carries a natural sym- plectic structure. Indeed, consider σjM . It's obviously skew-symmetric and closed. We must prove that σjM is non-degenerate. This is true because if ξ 2 TxMf0g and Jξ 2 TxM, so !(x)(ξ; Jξ) 6= 0 Definition 1.2. A submanifold in symplectic manifold (M; !) is La- 1 grangian if and only if !jTxL = 0 for all x 2 M and dim L = 2 dim M. -
Spin Structures on Exceptional Flag Manifolds
Castle Rauischholzhausen – March 2016 Lie Theory and Geometry Spin and metaplectic structures on homogeneous spaces (arXiv:1602.07968) (joint work with D. V. Alekseevsky) Ioannis Chrysikos Masaryk University – Department of Mathematics and Statistics 1 • (M n, g) connected oriented pseudo-Riemannian mnfd, signature (p, q) • π : P = SO(M) → M the SOp,q-principal bundle of positively oriented orthonormal frames. n TM = SO(M) ×SOp,q R = η− ⊕ η+, n Def. (M , g) is called time-oriented (resp. space-oriented) if η− (resp. η+) is oriented. 1 • time-oriented: if and only if H (M; Z2) 3 w1(η−) = 0 1 • space-oriented: if and only if H (M; Z2) 3 w1(η+) = 0 1 • oriented: if and only if H (M; Z2) 3 w1(M) := w1(TM) = w1(η−) + w1(η+) = 0 1 Examples: ⇒ Trivial line bundle M = S ×R, w1(M) = 0, 2 1 1 2 ⇒ Torus T = S × S , w1(T ) = 0 1 1 ; Möbius strip S = S ×GR → S , G = Z2, w1(S) =6 0 w1 =6 0 w1 = 0 1 ∼ Remark: Since H (M; Z2) = Hom(π1(M); Z2) ⇒ if M is simply-connected then it is oriented 2 p,q P∞ Nr p,q • C`p,q = C`(R ) = r=0 R / < x ⊗ x − hx, xi · 1 > 0 1 • C`p,q = C`p,q + C`p,q 0 p,q 0 • Spinp,q := {x1 ··· x2k ∈ C`p,q : xj ∈ R , hxj, xji = ±1} ⊂ C`p,q • Ad : Spinp,q → SOp,q double covering n Def. A Spinp,q-structure (shortly spin structure) on (M , g) • a Spinp,q-principal bundle π˜ : Q = Spin(M) → M over M, • a Z2-cover Λ : Spin(M) → SO(M) of π : SO(M) → M, such that: Spin(M) × Spinp,q / Spin(M) π˜ Λ×Ad Λ π $ SO(M) × SOp,q / SO(M) / M • If such a pair (Q, Λ) exists, we shall call (M n, g) a pseudo-Riemannian spin manifold.