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By applying the method of moving frames modelling one and two dimensional local anisotropies we construct new solutions of Einstein equations on pseudo-Riemannian spacetimes. The first class of solutions describes non-trivial deformations…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Sergiu I. Vacaru

We find general parameterizations for generic off-diagonal spacetime metrics and matter sources in general relativity (GR) and modified gravity theories when the field equations decouple with respect to certain types of nonholonomic frames…

General Relativity and Quantum Cosmology · Physics 2014-12-25 Tamara Gheorghiu , Olivia Vacaru , Sergiu I. Vacaru

Many papers on modified gravity theories (MGTs), and metric-affine geometry have been published. New classes of black hole (BH), wormhole (WH), and cosmological solutions involving nonmetricity and torsion fields were constructed.…

General Physics · Physics 2025-06-13 Sergiu I. Vacaru

Modified gravity theories (MGTs) have long been studied as alternatives to general relativity (GR) and the standard Lambda CDM cosmological model. For example, exponential f(R) models often yield better fits to observational data,…

General Physics · Physics 2026-05-01 Sergiu I. Vacaru

We model pseudo-Finsler geometries, with pseudo-Euclidean signatures of metrics, for two classes of four dimensional nonholonomic manifolds: a) tangent bundles with two dimensional base manifolds and b) pseudo-Riemannian/ Einstein…

General Relativity and Quantum Cosmology · Physics 2013-04-09 Sergiu I. Vacaru

For (2+2)-dimensional nonholonomic distributions, the physical information contained into a spacetime (pseudo) Riemannian metric can be encoded equivalently into new types of geometric structures and linear connections constructed as…

General Relativity and Quantum Cosmology · Physics 2010-04-08 Sergiu I. Vacaru

We study the fractional gravity for spacetimes with non-integer dimensions. Our constructions are based on a geometric formalism with the fractional Caputo derivative and integral calculus adapted to nonolonomic distributions. This allows…

Mathematical Physics · Physics 2012-04-20 Sergiu I. Vacaru

In the framework of non-riemannian geometry, we derive exact static vacuum solutions of the field equations obtained from the full equivalent version of the Einstein-Hilbert action when torsion degrees of freedom are taken into account. By…

General Relativity and Quantum Cosmology · Physics 2014-12-16 Rodrigo Maier

Mathematical modeling of gravitating configurations of physical fields is one of the priority directions of the modern theory of gravity. Most of the exact solutions constructed within the framework of the general relativity are static or…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Ju V Tchemarina , E G Alekseeva , A N Tsirulev , N K Nuraliev

Nonholonomic distributions and adapted fame structures on (pseudo) Riemannian manifolds of even dimension are employed to build structures equivalent to almost Kahler geometry and which allows to perform a Fedosov-like quantization of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergiu I. Vacaru

A general framework for the solutions of the constraints of pure gravity is constructed. It provides with well defined mathematical criteria to classify their solutions in four classes. Complete families of solutions are obtained in some…

General Relativity and Quantum Cosmology · Physics 2009-07-22 J. Martin , Antonio F. Rañada , A. Tiemblo

In the search for exact solutions to Einstein's field equations the main simplification tool is the introduction of spacetime symmetries. Motivated by this fact we develop a method to write the field equations for general matter in a form…

General Relativity and Quantum Cosmology · Physics 2014-11-17 E. Zafiris

Let $\mathbf{g}$ be a pseudo--Riemanian metric of arbitrary signature on a manifold $\mathbf{V}$ with conventional $n+n$ dimensional splitting, $\ n\geq 2,$ determined by a nonholonomic (non--integrable) distribution $\mathcal{N}$ defining…

Mathematical Physics · Physics 2017-01-20 Subhash Rajpoot , Sergiu I. Vacaru

We develop an approach to the theory nonholonomic relativistic stochastic processes on curved spaces. The Ito and Stratonovich calculus are formulated for spaces with conventional horizontal (holonomic) and vertical (nonholonomic) splitting…

Mathematical Physics · Physics 2012-03-27 Sergiu I. Vacaru

We study Finsler black holes induced from Einstein gravity as possible effects of quantum spacetime noncommutativity. Such Finsler models are defined by nonholonomic frames not on tangent bundles but on (pseudo) Riemannian manifolds being…

Mathematical Physics · Physics 2010-04-22 Sergiu I. Vacaru

We consider exact solutions of Einstein equations defining static black holes parametrized by off-diagonal metrics which by anholonomic mappings can be equivalently transformed into some diagonal metrics with coefficients being very similar…

High Energy Physics - Theory · Physics 2007-05-23 Sergiu I. Vacaru , Evghenii Gaburov

The Einstein equations for a plane-symmetric gravitational field coupled to an arbitrary nonlinear sigma model (NSM) are shown to be represented in the form of dynamical equations of a {\it generalized effective NSM}. The gravitational…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. V. Chervon , D. Yu. Shabalkin

A new framework to perturbative quantum gravity is proposed following the geometry of nonholonomic distributions on (pseudo) Riemannian manifolds. There are considered such distributions and adapted connections, also completely defined by a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Sergiu I. Vacaru

In this article we find the general, exact solution for the gravitational field equations for diagonal, vacuum, separable metrics. These are metrics each of whose terms can be separated into functions of each space-time variable separately.…

General Relativity and Quantum Cosmology · Physics 2010-10-05 Ron Lenk

We use an important decoupling property of gravitational field equations in the general relativity theory and modifications, written with respect to nonholonomic frames with 2+2 spacetime decomposition. This allows us to integrate the…

General Physics · Physics 2013-03-18 Sergiu I. Vacaru