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We define an index of the fermionic signature operator on even-dimensional globally hyperbolic spin manifolds of finite lifetime. The invariance of the index under homotopies is studied. The definition is generalized to causal fermion…

Mathematical Physics · Physics 2017-06-12 Felix Finster

We derive a cohomological formula for the analytic index of the Dirac-Ramond operator and we exhibit its modular properties.

High Energy Physics - Theory · Physics 2010-10-27 Orlando Alvarez , Paul Windey

We develop differential and symplectic geometry of differentiable Deligne-Mumford stacks (orbifolds) including Hamiltonian group actions and symplectic reduction. As an application we construct new examples of symplectic toric DM stacks as…

Symplectic Geometry · Mathematics 2011-12-07 Eugene Lerman , Anton Malkin

We establish an S^1-equivariant index theorem for Dirac operators on Z/k-manifolds. As an application, we generalize the Atiyah-Hirzebruch vanishing theorem for S^1-actions on closed spin manifolds to the case of Z/k-manifolds.

Differential Geometry · Mathematics 2007-05-23 Weiping Zhang

The main contribution of this manuscript is a local normal form for Hamiltonian actions of Poisson-Lie groups $K$ on a symplectic manifold equipped with an $AN$-valued moment map, where $AN$ is the dual Poisson-Lie group of $K$. Our proof…

Symplectic Geometry · Mathematics 2023-03-08 Megumi Harada , Jeremy Lane , Aidan Patterson

In this paper, we establish a certain inequality in terms of Betti numbers of a closed Hamiltonian $S^1$-manifold with isolated fixed points.

Symplectic Geometry · Mathematics 2019-11-12 Yunhyung Cho

We obtain explicit formulas for the rational homotopy groups of generalised symmetric spaces, i.e., the homogeneous spaces for which the isotropy subgroup appears as the fixed point group of some finite order automorphism of the group. In…

Algebraic Topology · Mathematics 2007-05-23 S. Terzic

We show that the Dirac operator on a compact globally hyperbolic Lorentzian spacetime with spacelike Cauchy boundary is a Fredholm operator if appropriate boundary conditions are imposed. We prove that the index of this operator is given by…

Differential Geometry · Mathematics 2019-10-01 Christian Baer , Alexander Strohmaier

We consider a connected symplectic manifold $M$ acted on by a connected Lie group $G$ in a Hamiltonian fashion. If $G$ is compact, we prove give an Equivalence Theorem for the symplectic manifolds whose squared moment map $\parallel \mu…

Differential Geometry · Mathematics 2007-05-23 Leonardo Biliotti

We generalize symplectic convexity theorems for Hamiltonian actions with proper momentum maps to symplectic actions on orbifolds with mod-$\Gamma$ proper momentum maps.

Symplectic Geometry · Mathematics 2007-05-23 Yang Qilin

In this paper we survey some recent results on actions of finite groups on topological manifolds. Given an action of a finite group $G$ on a manifold $X$, these results provide information on the restriction of the action to a subgroup of…

Geometric Topology · Mathematics 2023-12-19 Ignasi Mundet i Riera

We compute the index of the Dirac operator on spin Riemannian manifolds with conical singularities, acting from $L^p(\Sigma^+)$ to $L^q(\Sigma^-)$ with $p,q>1$. When $1+\frac{n}{p}-\frac{n}{q}>0$ we obtain the usual Atiyah-Patodi-Singer…

Differential Geometry · Mathematics 2007-05-23 André Legrand , Sergiu Moroianu

Let M be a weakly monotone symplectic manifold, and H be a time-dependent Hamiltonian; we assume that the periodic orbits of the corresponding time-dependent Hamiltonian vector field are non-degenerate. We construct a refined version of the…

Symplectic Geometry · Mathematics 2016-07-22 Kaoru Ono , Andrei Pajitnov

We revisit the cohomological index theorem for elliptic elements in the universal enveloping algebra of a Lie groupoid previously proved by the authors. We prove a Thom isomorphism for Lie algebroids which enables us to rewrite the…

Differential Geometry · Mathematics 2013-08-02 M. J. Pflaum , H. Posthuma , X. Tang

Consider a source proper, source connected regular symplectic groupoid acting locally freely and effectively in a Hamiltonian way, and assume that the moment map is proper and has connected fibres. In this case there is an associated…

Symplectic Geometry · Mathematics 2025-10-13 Luka Zwaan

The purpose of this article is to present a "Groupoid proof" to the Lefschetz fixed point formula for elliptic complexes. We shall define a "relative version" of tangent groupoid, describe the corresponding pseudodifferential calculi and…

Differential Geometry · Mathematics 2020-12-30 Zelin Yi

We study families of Dirac-type operators, with compatible perturbations, associated to wedge metrics on stratified spaces. We define a closed domain and, under an assumption of invertible boundary families, prove that the operators are…

Differential Geometry · Mathematics 2017-12-25 Pierre Albin , Jesse Gell-Redman

We study Fredholm properties and index formulas for Dirac operators over complete Riemannian manifolds with straight ends. An important class of examples of such manifolds are complete Riemannian manifolds with pinched negative sectional…

Differential Geometry · Mathematics 2019-02-20 Werner Ballmann , Jochen Brüning , Gilles Carron

We consider fully effective orientation-preserving smooth actions of a given finite group G on smooth, closed, oriented 3-manifolds M. We investigate the relations that necessarily hold between the numbers of fixed points of various…

Algebraic Topology · Mathematics 2014-10-01 Peter E. Frenkel

A time-dependent completely integrable Hamiltonian system is proved to admit the action-angle coordinates around any regular instantly compact invariant manifold. Written relative to these coordinates, its Hamiltonian and first integrals…

Dynamical Systems · Mathematics 2009-11-07 G. Giachetta , L. Mangiarotti , G. Sardanashvily