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Related papers: Reflections and spinors on manifolds

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This note contains some comments on a recent paper by Friedman on two-component spinors in spacetimes which do not admit a time-orientation, and is intended to clarify the relation of the work reported in that paper to previous literature.

General Relativity and Quantum Cosmology · Physics 2010-04-06 Andrew Chamblin , G. W. Gibbons

We obtain a continuous Wick rotation for Dirac, Majorana and Weyl spinors $\psi \to \exp ({1\over 2} \theta \gamma^4 \gamma^5)\psi$ which interpolates between Minkowski and Euclidean field theories.

High Energy Physics - Theory · Physics 2016-12-21 Peter van Nieuwenhuizen , Andrew Waldron

On a compact spin manifold we study the space of Riemannian metrics for which the Dirac operator is invertible. The first main result is a surgery theorem stating that such a metric can be extended over the trace of a surgery of codimension…

Differential Geometry · Mathematics 2011-07-21 Mattias Dahl

We consider the Lie derivative along Killing vector fields of the Dirac relativistic spinors: by using the polar decomposition we acquire the mean to study the implementation of symmetries on Dirac fields. Specifically, we will become able…

Mathematical Physics · Physics 2025-03-24 Luca Fabbri , Stefano Vignolo , Roberto Cianci

Chirality, handedness, is one of the most fundamental intriguing asymmetries in nature. By definition, chiral objects cannot be superimposed onto each other after mirror reflection operation. Numerous examples of chiral structures can be…

Mesoscale and Nanoscale Physics · Physics 2020-04-06 See-Hun Yang

In the paper, we give four different examples of the rescaled Dirac operator by the perturbation of the function f. Further, based on the trilinear Clifford multiplication by functional of differential one-forms, we compute the spectral…

Differential Geometry · Mathematics 2025-06-09 Tong Wu , Yong Wang

In the first part of the paper we give a tensor version of the Dirac equation. In the second part we formulate and analyse a simple model equation which for weak external fields appears to have properties similar to those of the…

Mathematical Physics · Physics 2018-08-14 Daniel M. Elton , Dmitri Vassiliev

This article gives a geometric interpretation of the spin base formulation with local spin base invariance of spinors on a curved space-time and in particular of a central element, the global Dirac structure, in terms of principal and…

High Energy Physics - Theory · Physics 2022-05-04 Claudio Emmrich

Part I: The geometric algebra of space is derived by extending the real number system to include three mutually anticommuting square roots of plus one. The resulting geometric algebra is isomorphic to the algebra of complex 2x2 matrices,…

Mathematical Physics · Physics 2015-07-24 Garret Sobczyk

It is proved that there exist a vector representation of Dirac's spinor field and in one sense it is equivalent to biquaternion (i.e. complexified quaternion) representation. This can be considered as a generalization of Cartan's idea of…

High Energy Physics - Theory · Physics 2007-05-23 Liu Yu-Fen

I review the current status of hadronic structure computations on the lattice. I describe the basic lattice techniques and difficulties and present some of the latest lattice results; in particular recent results of the RBC group using…

High Energy Physics - Lattice · Physics 2009-11-07 Konstantinos Orginos

Relativistic spin-1/2 particles in curved spacetime are naturally described by Dirac theory, which is a dynamical and Lorentz-invariant field theory. In this work, we propose a non-dynamical fermion theory in 3+1 dimensions dubbed spinor…

High Energy Physics - Theory · Physics 2016-07-20 Giandomenico Palumbo

We prove upper and lower bounds for the eigenvalues of the Dirac operator and the Laplace operator on 2-dimensional tori. In particluar we give a lower bound for the first eigenvalue of the Dirac operator for non-trivial spin structures. It…

Differential Geometry · Mathematics 2007-05-23 Bernd Ammann

It is known that, for Dirac operators on Riemann surfaces twisted by line bundles with Hermitian-Einstein connections, it is possible to obtain estimates for the first eigenvalue in terms of the topology of the twisting bundle \cite{JL2}.…

Differential Geometry · Mathematics 2013-10-15 Rafael F. Leão

In gravitation theory, the realistic fermion matter is described by spinor bundles associated with the cotangent bundle of a world manifold $X$. In this case, the Dirac operator can be introduced. There is the 1:1 correspondence between…

General Relativity and Quantum Cosmology · Physics 2016-08-31 G. Sardanashvily

Exotic spinor fields arise from inequivalent spin structures on non-trivial topological manifolds, $M$. This induces an additional term in the Dirac operator, defined by the cohomology group $H^1(M,\mathbb{Z}_2)$ that rules a Cech…

High Energy Physics - Theory · Physics 2020-10-28 R. da Rocha , A. A. Tomaz

This paper discusses a framework to parametrize and decompose operator matrix elements for particles with higher spin $(j > 1/2)$ using chiral representations of the Lorentz group, i.e. the $(j,0)$ and $(0,j)$ representations and their…

High Energy Physics - Phenomenology · Physics 2025-12-16 Wim Cosyn , Frank Vera

Some new expressions are found, concerning the one-loop effective action of four dimensional massive and massless Dirac fermions in the presence of general uniform electric and magnetic fields, with $\vec E\cdot \vec H\neq 0$ and $\vec E…

High Energy Physics - Theory · Physics 2009-10-31 Roberto Soldati , Lorenzo Sorbo

In his book Mickelsson notices that the infinite-dimensional Grassmannian manifold of Segal and Wilson admits a Spin^c structure and after this he naturally considers the problem of defining a Dirac operator on it. Mickelsson gives a…

Representation Theory · Mathematics 2010-07-27 Vesa Tahtinen

In this paper, we consider a general twisted-curved space-time hosting Dirac spinors and we take into account the Lorentz covariant polar decomposition of the Dirac spinor field: the corresponding decomposition of the Dirac spinor field…

General Physics · Physics 2018-12-06 Luca Fabbri