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Related papers: Nonlinear spinor field with Lyras geometry: Bianch…

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Different characteristic of matter influencing the evolution of the Universe has been simulated by means of a nonlinear spinor field. We have considered two cases where the spinor field nonlinearity occurs either as a result of self-action…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

In the course of investigation of our present universe by considering the five-dimensional locally rotationally symmetric (LRS) Bianchi type-I universe with time-dependent deceleration parameters in Lyra manifold, it is excitingly found…

General Physics · Physics 2019-02-01 Kangujam Priyokumar Singh , Mahbubur Rahman Mollah

Within the scope of anisotropic non-diagonal Bianchi type-II, VIII and IX spacetime it is shown that the off-diagonal components of the corresponding metric impose severe restrictions on the components of the energy momentum tensor in…

General Relativity and Quantum Cosmology · Physics 2020-07-17 Bijan Saha

This paper investigates the possible cosmological implications of the presence of an antisymmetric tensor field related to a lack of commutatitivity of spacetime coordinates at the Planck era. For this purpose, such a field is promoted to a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Elisabetta Di Grezia , Giampiero Esposito , Agostino Funel , Gianpiero Mangano , Gennaro Miele

We consider Bianchi VI spacetime, which also can be reduced to Bianchi types VI0-V-III-I. We initially consider the most general form of the energy-momentum tensor which yields anisotropic stress and heat flow. We then derive an…

General Relativity and Quantum Cosmology · Physics 2011-08-26 Ozgur Akarsu , Can B. Kilinc

Self-consistent system of spinor, scalar and BI gravitational fields is considered. Exact solutions to the field equations in terms of volume scale of the BI metric are obtained. Einstein field equations in account of the cosmological…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bijan Saha , Todor Boyadjiev

Self-consistent solutions to nonlinear spinor field equations in General Relativity have been studied for the case of Bianchi type-I space-time filled with perfect fluid. The initial and the asymptotic behavior of the field functions and…

General Relativity and Quantum Cosmology · Physics 2009-10-28 B. Saha , G. N. Shikin

Within the scope of an anisotropic Bianchi type-V cosmological model we have studied the evolution of the universe. The assumption of a diagonal energy-momentum tensor leads to some severe restriction on the metric functions, which on its…

General Physics · Physics 2015-05-01 Bijan Saha

The Dirac field is studied in a Lyra space-time background by means of the classical Schwinger Variational Principle. We obtain the equations of motion, establish the conservation laws, and get a scale relation relating the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2008-11-26 R. Casana , C. A. M. de Melo , B. M. Pimentel

We introduce and carefully define an entire class of field theories based on non-standard spinors. Their dominant interaction is via the gravitational field which makes them naturally dark; we refer to them as Dark Spinors. We provide a…

High Energy Physics - Theory · Physics 2012-12-11 Christian G. Boehmer , James Burnett , David F. Mota , Douglas J. Shaw

We study the effects produced by nonlinear electrodynamics in spacetimes conformal to Bianchi metrics. In the presence of Born-Infeld type fields these models accelerate, expand and isotropize. This effect is compared with the corresponding…

High Energy Physics - Theory · Physics 2009-11-07 Ricardo Garcia-Salcedo , Nora Breton

Self-consistent system of nonlinear spinor field and Bianchi I (BI) gravitational one with time dependent gravitational constant ($G$) and cosmological constant ($\Lambda$) has been studied. The initial and the asymptotic behaviors of the…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

We study spinor field theories as an origin to induce space-time evolution. Self-interacting spinor fields with canonical and non-canonical kinetic terms are considered in a Friedman-Robertson-Walker universe. The deceleration parameter is…

High Energy Physics - Phenomenology · Physics 2015-05-27 Tomohiro Inagaki , Yury Rybalov , Xinhe Meng

In the framework of axionically extended Einstein-Maxwell-aether theory we study the structure of the electromagnetic field allowed by the anisotropic cosmological spacetime platforms associated with the Bianchi models. These models…

General Relativity and Quantum Cosmology · Physics 2023-04-17 Amir F. Shakirzyanov , Alexander B. Balakin

We consider a system of nonlinear spinor and scalar fields with minimal coupling in general relativity. The nonlinearity in the spinor field Lagrangian is given by an arbitrary function of the invariants generated from the bilinear spinor…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bijan Saha , G. N. Shikin

This paper delves into the deformation of spinor structures within nontrivial topologies and their physical implications. The deformation is modeled by introducing real functions that modify the standard spinor dynamics, leading to distinct…

Mathematical Physics · Physics 2025-02-19 J. M. Hoff da Silva , R. T. Cavalcanti , G. M. Caires da Rocha

Exotic spinors arise in non-simply connected base manifolds due to the nonequivalent spinor structure. The dynamics of exotic spinors are endowed with an additional differential factor. In this work, we merge the exotic spinor scenario with…

Mathematical Physics · Physics 2023-01-31 J. M. Hoff da Silva , R. T. Cavalcanti , D. Beghetto , G. M. Caires da Rocha

Within the framework of Bianchi type-II (BII) cosmological model the behavior of matter distribution has been considered. It is shown that the non-zero off-diagonal component of Einstein tensor implies some severe restriction on the choice…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

The theory of spinors is developed for locally anisotropic (la) spaces, in brief la-spaces, which in general are modeled as vector bundles provided with nonlinear and distinguished connections and metric structures (such la-spaces contain…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Sergiu I. Vacaru

We study the properties of the energy-momentum tensor of gauge fields coupled to matter in non-commutative (Moyal) space. In general, the non-commutativity affects the usual conservation law of the tensor as well as its transformation…

High Energy Physics - Theory · Physics 2015-06-26 Herbert Balasin , Daniel N. Blaschke , Francois Gieres , Manfred Schweda