15 research outputs found
Representation of spinors in the n-dimensional space by a system of tensors
Representation of spinors in n-dimensional space by complex and real systems of tensor
Comparative evaluation of different radical initiators, used for production of graft copolymers, based on atactic polypropylene
Hestenes' Tetrad and Spin Connections
Defining a spin connection is necessary for formulating Dirac's bispinor
equation in a curved space-time. Hestenes has shown that a bispinor field is
equivalent to an orthonormal tetrad of vector fields together with a complex
scalar field. In this paper, we show that using Hestenes' tetrad for the spin
connection in a Riemannian space-time leads to a Yang-Mills formulation of the
Dirac Lagrangian in which the bispinor field is mapped to a set of Yang-Mills
gauge potentials and a complex scalar field. This result was previously proved
for a Minkowski space-time using Fierz identities. As an application we derive
several different non-Riemannian spin connections found in the literature
directly from an arbitrary linear connection acting on Hestenes' tetrad and
scalar fields. We also derive spin connections for which Dirac's bispinor
equation is form invariant. Previous work has not considered form invariance of
the Dirac equation as a criterion for defining a general spin connection
Interacting spinor and scalar fields in Bianchi type-I Universe filled with viscous fluid: exact and numerical solutions
We consider a self-consistent system of spinor and scalar fields within the
framework of a Bianchi type I gravitational field filled with viscous fluid in
presence of a term. Exact self-consistent solutions to the
corresponding spinor, scalar and BI gravitational field equations are obtained
in terms of , where is the volume scale of BI universe. System of
equations for and \ve, where \ve is the energy of the viscous fluid,
is deduced. Some special cases allowing exact solutions are thoroughly studied.Comment: 18 pages, 6 figure
Spinor Field in Bianchi type-I Universe: regular solutions
Self-consistent solutions to the nonlinear spinor field equations in General
Relativity has been studied for the case of Bianchi type-I (B-I) space-time. It
has been shown that, for some special type of nonliearity the model provides
regular solution, but this singularity-free solutions are attained at the cost
of broken dominant energy condition in Hawking-Penrose theorem. It has also
been shown that the introduction of -term in the Lagrangian generates
oscillations of the B-I model, which is not the case in absence of
term. Moreover, for the linear spinor field, the term provides
oscillatory solutions, those are regular everywhere, without violating dominant
energy condition.
Key words: Nonlinear spinor field (NLSF), Bianch type -I model (B-I),
term
PACS 98.80.C CosmologyComment: RevTex, 21 page