English
Related papers

Related papers: Exact Solutions in Modified Massive Gravity and Of…

200 papers

We study new classes of generic off-diagonal and diagonal cosmological solutions for effective Einstein equations in modified gravity theories, MGTs, with modified dispersion relations, MDRs, encoding possible violations of (local) Lorentz…

General Physics · Physics 2021-06-02 Panayiotis Stavrinos , 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

We elaborate on the anholonomic frame deformation method, AFDM, for constructing exact solutions with quasiperiodic structure in modified gravity theories, MGTs, and general relativity, GR. Such solutions are described by generic…

General Physics · Physics 2018-05-29 Laurenţiu Bubuianu , Sergiu I. Vacaru

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

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

The paper deals with the static spherically symmetric wormhole solutions in $f(R)$-modified gravity theory with anisotropic matter field and for some particular choices for the shape functions. The present work may be considered as an…

General Relativity and Quantum Cosmology · Physics 2021-08-11 Bikram Ghosh , Saugata Mitra , Subenoy Chakraborty

We prove that the Einstein equations can be solved in a very general form for arbitrary spacetime dimensions and various types of vacuum and non-vacuum cases following a geometric method of anholonomic frame deformations for constructing…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Sergiu I. Vacaru

On the basis of exact solutions to the Einstein-Abelian gauge-dilaton equations in $D$-dimensional gravity, the properties of static axial configurations are discussed. Solutions free of curvature singularities are selected; they can be…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Kirill A. Bronnikov , Julio C. Fabris

This article is a status report on the Anholonomic Frame and Connection Deformation Method, AFCDM, for constructing generic off-diagonal exact and parametric solutions in general relativity, GR, relativistic geometric flows, and modified…

General Relativity and Quantum Cosmology · Physics 2025-10-07 Laurenţiu Bubuianu , Julia O. Seti , Douglas Singleton , Panayiotis Stavrinos , Sergiu I. Vacaru , Elşen Veli Veliev

Using a new ansatz for solving the Einstein equations with a scalar field with the sign of the kinetic term inverted, I find a series of formulae to derive axial symmetric stationary exact solutions of the Phantom scalar field in general…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Tonatiuh Matos

We give here a list of exact classical solutions of a large class of weakly nonlocal theories of gravity, which are unitary and super-renormalizable (or finite) at quantum level. It is explicitly shown that flat and Ricci-flat spacetimes as…

High Energy Physics - Theory · Physics 2016-01-27 Yao-Dong Li , Leonardo Modesto , Leslaw Rachwal

We construct exact black hole solutions to Einstein gravity with nonlinear electrodynamic field. In these solutions, there are in general four parameters. They are physical mass, electric charge, cosmological constant and the coupling…

General Relativity and Quantum Cosmology · Physics 2020-05-27 Shuang Yu , Changjun Gao

We prove the existence of hidden symmetries in the general relativity theory defined by exact solutions with generic off-diagonal metrics, nonholonomic (non-integrable) constraints, and deformations of the frame and linear connection…

Mathematical Physics · Physics 2013-02-12 Sergiu I. Vacaru

In this paper, we construct exact rotating wormholes using Ehlers solution-generating technique. This is based on the Ernst description of four-dimensional, stationary, and axially symmetric solutions of the Einstein-Maxwell theory. We…

General Relativity and Quantum Cosmology · Physics 2023-08-09 Adolfo Cisterna , Keanu Müller , Konstantinos Pallikaris , Adriano Viganò

Noncommutative geometry, an offshoot of string theory, replaces point-like particles by smeared objects. These local effects have led to wormhole solutions in a semiclassical setting, but it has also been claimed that the noncommutative…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Peter K. F. Kuhfittig

We outline a new geometric method of constructing exact solutions of gravitational field equations parametrized by generic off-diagonal metrics, anholonomic frames and possessing, in general, nontrivial torsion and nonmetricity. The…

Differential Geometry · Mathematics 2007-05-23 Sergiu I. Vacaru

We construct a new class of exact solutions describing spacetimes possessing Lie algebroid symmetry. They are described by generic off-diagaonal 5D metrics embedded in bosonic string gravity and possess nontrivial limits to the Einstein…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sergiu I. Vacaru

Modified gravity theories, MGTs, with modified (nonlinear) dispersion relations, MDRs, encode via indicator functionals possible modifications and effects of quantum gravity; in string/brane, noncommutative and/or nonassociative gravity…

General Physics · Physics 2020-01-31 Laurenţiu Bubuianu , Sergiu I. Vacaru

The horizon and geodesic structure of static configurations generated by anisotropic conformal transforms of the Schwarzschild metric is analyzed. We construct the maximal analytic extension of such off--diagonal vacuum metrics and conclude…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Sergiu Vacaru , D. E. Goksel

This paper discusses several new exact solutions of static wormholes in $f(R)$ gravity with a noncommutative-geometry background, which replaces point-like structures by smeared objects. In the first part of the paper we assume the…

General Relativity and Quantum Cosmology · Physics 2014-10-21 Mubasher Jamil , Farook Rahaman , Ratbay Myrzakulov , P. K. F. Kuhfittig , Nasr Ahmed , Umar F Mondal