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Related papers: Dirac cohomology and character lifting

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We consider the theory of spinor fields written in polar form and we re-express it in terms of the so-called 1+1+2 covariant splitting: after this is done for the basic kinematic variables, we proceed to decompose the dynamical equations,…

Mathematical Physics · Physics 2025-07-24 Luca Fabbri , Stefano Vignolo , Giuseppe De Maria , Sante Carloni

Odd-dimensional Riemannian spaces that are non-orientable, but have a pin structure, require the consideration of the twisted adjoint representation of the corresponding pin group. It is shown here how the Dirac operator should be modified,…

High Energy Physics - Theory · Physics 2011-04-15 Andrzej Trautman

We define an analogue of the Dirac operator for the degenerate affine Hecke-Clifford algebra. A main result is to relate the central characters of the degenerate affine Hecke-Clifford algebra with the central characters of the Sergeev…

Representation Theory · Mathematics 2015-04-28 Kei Yuen Chan

We give a min-max characterization of the weighted Dirac eigenvalues, and show that the weighted eigenvalues and eigenspaces of Dirac operators are continuous with respect to weak $L^p$ convergence of the inverse weight, for any $p>n$.…

Spectral Theory · Mathematics 2025-08-28 Zixuan Qiu , Ruijun Wu

Previously (A. Akhmeteli, J. Math. Phys., v. 52, p. 082303 (2011)), the Dirac equation in an arbitrary electromagnetic field was shown to be generally equivalent to a fourth-order equation for just one component of the four-component Dirac…

Quantum Physics · Physics 2022-04-26 Andrey Akhmeteli

Let U(N) be the quasi-split unitary group in N variables for a quadratic unramified extension of p-adic fields. We compute the characters of simple supercuspidal representations of twisted GL(N) and U(N). Comparing them by the endoscopic…

Number Theory · Mathematics 2018-10-16 Masao Oi

We study general conditions under which the computations of the index of a perturbed Dirac operator $D_{s}=D+sZ$ localize to the singular set of the bundle endomorphism $Z$ in the semi-classical limit $s\to \infty $. We show how to use…

Differential Geometry · Mathematics 2015-06-26 Igor Prokhorenkov , Ken Richardson

In this note, we give a geometric expression for the multiplicities of the equivariant index of a Dirac operator twisted by a line bundle.

Symplectic Geometry · Mathematics 2014-04-09 Paul-Emile Paradan , Michèle Vergne

In this paper, we define two generalisations of Dirac operators for Drinfeld's Hecke algebra. One generalisation, Parthasarathy operators inherit the notion of the Dirac inequality. The second generalisation, warped Dirac operators are such…

Representation Theory · Mathematics 2024-03-12 Kieran Calvert

For a compact spin manifold $M$ isometrically embedded into Euclidean space, we derive the extrinsic estimates from above and below for eigenvalues of the Dirac operators, which depend on the second fundamental form of the embedding. We…

Differential Geometry · Mathematics 2007-05-23 Daguang Chen

Arc permutations, which were originally introduced in the study of triangulations and characters, have recently been shown to have interesting combinatorial properties. The first part of this paper continues their study by providing signed…

Combinatorics · Mathematics 2014-09-18 Sergi Elizalde , Yuval Roichman

The equivariant cohomology ring of a regular semisimple Hessenberg variety in type A is a free module over the equivariant cohomology ring of a point. When equipped with Tymoczko's dot action, it becomes a twisted representation of the…

Combinatorics · Mathematics 2025-07-09 Mathieu Guay-Paquet

We study the theta lifting for real unitary groups and completely determine the theta lifts of tempered representations. In particular, we show that the theta lifts of (limits of) discrete series representations can be expressed as…

Representation Theory · Mathematics 2021-07-07 Atsushi Ichino

Up to equivalence, this paper classifies all the irreducible unitary representations with non-zero Dirac cohomology for the following simple real exceptional Lie groups: ${\rm EI}=E_{6(6)}, {\rm EIV}=E_{6(-26)}, {\rm FI}=F_{4(4)}, {\rm…

Representation Theory · Mathematics 2020-05-12 Jian Ding , Chao-Ping Dong , Liang Yang

An index theory for projective families of elliptic pseudodifferential operators is developed. The topological and the analytic index of such a family both take values in twisted K-theory of the parametrizing space, X. The main result is…

Differential Geometry · Mathematics 2014-11-11 Varghese Mathai , Richard B Melrose , Isadore M Singer

We define (higher rank) spinorially twisted spin structures and deduce various curvature identites as well as estimates for the eigenvalues of the corresponding twisted Dirac operators.

Differential Geometry · Mathematics 2016-05-19 Malors Espinosa , Rafael Herrera

We study the Dirac cohomology of supermodules over basic classical Lie superalgebras, formulated in terms of cubic Dirac operators associated with parabolic subalgebras. Specifically, we establish a super-analog of the Casselman-Osborne…

Representation Theory · Mathematics 2026-03-03 Simone Noja , Steffen Schmidt , Raphael Senghaas

Using the Arthur-Selberg trace formula we express the index of a Dirac operator on an arithmetic quotient over a totally real field with at least two real embeddings as the integral over the index form plus a sum of orbital integrals. For…

dg-ga · Mathematics 2008-02-03 Anton Deitmar

We describe the Dirac monopole using the Cheeger-Simons differential characters. We comment on the r\^{o}le of the Dirac string and on the connection with Deligne cohomology.

Mathematical Physics · Physics 2007-05-23 Nikos Kalogeropoulos

A novel spherical convolution is defined through the sifting property of the Dirac delta on the sphere. The so-called sifting convolution is defined by the inner product of one function with a translated version of another, but with the…

Information Theory · Computer Science 2023-04-24 Patrick J. Roddy , Jason D. McEwen