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We develop a novel approach to gravity in which gravity is described by a matrix-valued symmetric two-tensor field and construct an invariant functional that reduces to the standard Einstein-Hilbert action in the commutative limit. We also…

High Energy Physics - Theory · Physics 2007-05-23 Ivan Avramidi

This is an introduction to an algebraic construction of a gravity theory on noncommutative spaces which is based on a deformed algebra of (infinitesimal) diffeomorphisms. We start with some fundamental ideas and concepts of noncommutative…

High Energy Physics - Theory · Physics 2007-05-23 Frank Meyer

We study a deformation of infinitesimal diffeomorphisms of a smooth manifold. The deformation is based on a general twist. This leads to a differential geometry on a noncommutative algebra of functions whose product is a star-product. The…

High Energy Physics - Theory · Physics 2009-11-11 Paolo Aschieri , Marija Dimitrijevic , Frank Meyer , Julius Wess

A covariant reformulation of General Relativity is briefly considered from three points of view: geometrodynamics, Lagrange-Euler field theory, and gauge field theory. From a geometrodynamics perspective, a definition of the reference frame…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Alexander Poltorak

We study a non-commutative deformation of general relativity based on spectral invariants of a partial differential operator acting on sections of a vector bundle over a smooth manifold. We compute the first non-commutative corrections to…

General Relativity and Quantum Cosmology · Physics 2011-02-17 Guglielmo Fucci , Ivan G. Avramidi

We study general relativity in the framework of non-commutative differential geometry. In particular, we introduce a gravity action for a space-time which is the product of a four dimensional manifold by a two-point space. In the simplest…

High Energy Physics - Theory · Physics 2008-11-26 A. H. Chamseddine , G. Felder , J. Fröhlich

Starting with a field theoretic approach in Minkowski space, the gravitational energy momentum tensor is derived from the Einstein equations in a straightforward manner. This allows to present them as {\it acceleration tensor} = const.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Theo M. Nieuwenhuizen

Using Fedosov theory of deformation quantization of endomorphism bundle we construct several models of pure geometric, deformed vacuum gravity, corresponding to arbitrary symplectic noncommutativity tensor. Deformations of Einstein-Hilbert…

High Energy Physics - Theory · Physics 2011-09-29 Michal Dobrski

It is well known that the Einstein-Hilbert action in two dimensions is topological and yields an identically vanishing Einstein tensor. Consequently one is faced with difficulties when formulating a non-trivial gravity model. We present a…

General Relativity and Quantum Cosmology · Physics 2024-06-10 Christian G. Boehmer , Erik Jensko

A calculation by Jacobson [1] strongly implies that the field equations which describe gravity are emergent phenomena. In this paper, the method is extended to the case of a non-commutative spacetime. By making use of a non-commutative…

High Energy Physics - Theory · Physics 2015-05-21 Simon Moolman

A deformation of the algebra of diffeomorphisms is constructed for canonically deformed spaces with constant deformation parameter theta. The algebraic relations remain the same, whereas the comultiplication rule (Leibniz rule) is different…

High Energy Physics - Theory · Physics 2007-05-23 Paolo Aschieri , Christian Blohmann , Marija Dimitrijevic , Frank Meyer , Peter Schupp , Julius Wess

A formulation of Einstein's gravitational field equations in four space-time dimensions is presented using generalized differential forms and Cartan's equations for metric geometries. Cartan's structure equations are extended by using…

General Relativity and Quantum Cosmology · Physics 2025-10-21 D C Robinson

In contrast to electrodynamics, Einstein's gravitation equations are not invariant with respect to a wide class of the mapping of field variables which leave equations of motion of test particles in a given coordinate system invariant. It…

General Relativity and Quantum Cosmology · Physics 2008-05-20 Leonid Verozub

Einstein's equations in matter are gravitational analogues of Maxwell's equations in matter, providing an effective classical description of gravitational fields. We derive Einstein's equations in matter for relativistic fluids, and use…

General Relativity and Quantum Cosmology · Physics 2020-05-29 Pavel Kovtun , Ashish Shukla

Starting from noncommutative generalization of Minkowski space we consider quantum deformed relativistic symmetries which lead to the modification of kinematics of special relativity. The noncommutative field theory framework described by…

High Energy Physics - Theory · Physics 2015-05-18 Jerzy Lukierski

Here show that, pure affine actions based solely on the Riemann curvature tensor lead to Einstein field equations for gravitation. The matter and radiation involved are general enough to impose no restrictions on material dynamics or vacuum…

High Energy Physics - Theory · Physics 2017-09-27 Durmus Demir , Oktay Dogangun , Tonguc Rador , Selin Soysal

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

The equations of motion for matter fields are invariant under the shift of the matter lagrangian by a constant. Such a shift changes the energy momentum tensor of matter by T^a_b --> T^a_b +\rho \delta^a_b. In the conventional approach,…

General Relativity and Quantum Cosmology · Physics 2008-11-26 T. Padmanabhan

We study a noncommutative theory of gravity in the framework of torsional spacetime. This theory is based on a Lagrangian obtained by applying the technique of dimensional reduction of noncommutative gauge theory and that the yielded…

General Physics · Physics 2014-12-30 Aref Yazdani

We derive the full set of field equations based on Hossenfelder's recent covariant formulation of the emergent gravity model, along with perturbative and exact solutions. The exact solution describes a static, spherically-symmetric…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Yen-Kheng Lim , Qing-hai Wang
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