نتایج جستجو برای: torsion theory

تعداد نتایج: 798181  

2004
Biswarup Mukhopadhyaya Soumitra SenGupta

The possibility of parity violation in a gravitational theory with torsion is extensively explored in four and higher dimensions. In the former case, we have listed our conclusions on when and whether parity ceases to be conserved, with both two-and three-index antisymmetry of the torsion field. In the latter, the bulk spacetime is assumed to have torsion, and the survival of parity-violating t...

2008
Fabrizio Canfora Alex Giacomini

In this paper new exact solutions in eight dimensional Lovelock theory will be presented. These solutions are vacuum static wormhole, black hole and generalized Bertotti-Robinson space-times with nontrivial torsion. All the solutions have a cross product structure of the type M5 × Σ3 where M5 is a five dimensional manifold and Σ3 a compact constant curvature manifold. The wormhole is the first ...

Journal: :Formalized Mathematics 2014
Yuichi Futa Hiroyuki Okazaki Kazuhisa Nakasho Yasunari Shidama

In this article, we formalize a torsion Z-module and a torsionfree Z-module. Especially, we prove formally that finitely generated torsion-free Z-modules are finite rank free. We also formalize properties related to rank of finite rank free Z-modules. The notion of Z-module is necessary for solving lattice problems, LLL (Lenstra, Lenstra, and Lovász) base reduction algorithm [20], cryptographic...

2006
Dan Burghelea Stefan Haller

In this paper we extend Witten–Helffer–Sjöstrand theory from selfadjoint Laplacians based on fiber wise Hermitian structures, to non-selfadjoint Laplacians based on fiber wise non-degenerate symmetric bilinear forms. As an application we verify, up to sign, the conjecture about the comparison of the Milnor–Turaev torsion with the complex valued analytic torsion, for odd dimensional manifolds. T...

Journal: :Epj Web of Conferences 2021

The increasing interest to improve the description of plastic behavior and fracture prediction for ductile materials under complex loading conditions conducted researchers overcome J2 plasticity theory. To do this more sophisticated model base on damage have been implemented. Material parameters must be identified by means proper testing calibration procedures requiring different conditions. Di...

2015
Sebastian Bahamonde Matthew Wright

We propose a new model in the teleparallel framework where we consider a scalar field nonminimally coupled to both the torsion T and a boundary term given by the divergence of the torsion vector B 1⁄4 2e ∂μðeTμÞ. This is inspired by the relation R 1⁄4 −T þ B between the Ricci scalar of general relativity and the torsion of teleparallel gravity. This theory in suitable limits incorporates both t...

2003
DAVID ROSENTHAL

In this work, the assembly map in L-theory for the family of finite subgroups is proven to be a split injection for a class of groups. Groups in this class, including virtually polycyclic groups, have universal spaces that satisfy certain geometric conditions. The proof follows the method developed by Carlsson-Pedersen to split the assembly map in the case of torsion free groups. Here, the cont...

2005
R. Casana C. A. M. de Melo B. M. Pimentel

The problem of coupling between spin and torsion is analysed from a Lyra's manifold background for scalar and vector massive fields using the Duffin-Kemmer-Petiau (DKP) theory. We found the propagation of the torsion is dynamical, and the minimal coupling of DKP field corresponds to a non-minimal coupling in the standard Klein-Gordon-Fock and Proca approaches. The origin of this difference in t...

2009
Biswarup Mukhopadhyaya Soumitra SenGupta

We consider a string-inspired torsion-dilaton-gravity action in a Randall-Sundrum brane world scenario and show that, in an effective four-dimensional theory on the visible brane, the rank-2 antisymmetric Kalb-Ramond field (source of torsion) is exponentially suppressed. The result is similar to our earlier result in [13], where no dilaton was present in the bulk. This offers an explanation of ...

2003
G. Aprea G. Montani R. Ruffini

Working in the lagrangian framework, we develop a geometric theory in vacuum with propagating torsion; the antisymmetric and trace parts of the torsion tensor, considered as derived from local potential fields, are taken and, using the minimal action principle, their field equations are calculated. Actually these will show themselves to be just equations for propagating waves giving torsion a b...

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