8 research outputs found
A locally anisotropic geometrical model of space-time based on CMBR
We study a locally anisotropic model of General Relativity in the framework
of a more general geometrical structure than the Riemannian one. In this model
the observable anisotropy of the CMBR (WMAP) is represented by a tensor of
anisotropy and it is included in the metric structure of space-time. As well,
some interesting special cases of spaces are considered.Comment: 5 pages, 0 figures, 7th International Astronomy Conference of the
Hellenic Astronomical Society, curvature and connection sections decreased,
minor explanation added, fixed some typo
Bounce cosmology in generalized modified gravities
We investigate the bounce realization in the framework of generalized
modified gravities arising from Finsler and Finsler-like geometries. In
particular, the richer intrinsic geometrical structure is reflected in the
appearance of extra degrees of freedom in the Friedmann equations that can
drive the bounce. We examine various Finsler and Finsler-like constructions. In
the cases of general very special relativity as well as of Finsler-like gravity
on the tangent bundle we show that a bounce cannot be easily obtained. However,
in the Finsler-Randers space the induced scalar anisotropy can fulfill the
bounce conditions and bouncing solutions are easily obtained. Finally, for the
general class of theories that include a nonlinear connection a new scalar
field is induced, leading to a scalar-tensor structure that can easily drive a
bounce. These features reveal the capabilities of Finsler and Finsler-like
geometries.Comment: 10 pages, 3 figures, to appear in Univers
Cyclic and Ekpyrotic Universes in Modified Finsler Osculating Gravity on Tangent Lorentz Bundles
We consider models of accelerating Universe elaborated for Finsler like
gravity theories constructed on tangent bundles to Lorentz manifolds. In the
osculating approximation, certain locally anisotropic configurations are
similar to those for f(R) gravity. This allows us to generalize a proposal (by
Nojiri, Odintsov and Saez-Gomez, arXiv: 1108.0767) in order to reconstruct and
compare two classes of Einstein-Finsler gravity, EFG, and f(R) gravity theories
using modern cosmological data and realistic physical scenarios. We conclude
that EFG provides inflation, acceleration and little rip evolution scenarios
with realistic alternatives to standard Lambda CDM cosmology. The approach is
based on a proof that there is a general decoupling property of gravitational
field equations in EFG and modified theories which allows us to generate
off-diagonal cosmological solutions.Comment: latex2e, 28 pages, version accepted by CQG, with modifications and
additional explanations and new references requested by referee
Nonholonomic ricci flows and Finsler-Lagrange f(R,F,L)-modified gravity and dark matter effects
We review the theory of geometric flows on nonholonomic manifolds and tangent bundles and self-similar configurations resulting in generalized Ricci solitons and Einstein-Finsler equations. There are provided new classes of exact solutions on Finsler-Lagrange f(R,F,L)-modifications of general relativity and discussed possible implications in acceleration cosmology