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We study a noncommutative deformation of general relativity where the gravitational field is described by a matrix-valued symmetric two-tensor field. The equations of motion are derived in the framework of this new theory by varying a…

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

We study noncommutative deformations of the wave equation in curved backgrounds and discuss the modification of the dispersion relations due to noncommutativity combined with curvature of spacetime. Our noncommutative differential geometry…

General Relativity and Quantum Cosmology · Physics 2021-04-14 Paolo Aschieri , Andrzej Borowiec , Anna Pachoł

We consider a noncommutative field theory with space-time $\star$-commutators based on an angular noncommutativity, namely a solvable Lie algebra: the Euclidean in two dimension. The $\star$-product can be derived from a twist operator and…

High Energy Physics - Theory · Physics 2018-10-17 Marija Dimitrijevic Ciric , Nikola Konjik , Maxim A. Kurkov , Fedele Lizzi , Patrizia Vitale

We define a noncommutative Lorentz symmetry for canonical noncommutative spaces. The noncommutative vector fields and the derivatives transform under a deformed Lorentz transformation. We show that the star product is invariant under…

High Energy Physics - Theory · Physics 2009-11-10 Xavier Calmet

We investigate the effects of space noncommutativity and the generalized uncertainty principle on the stability of circular orbits of particles in both a central force potential and Schwarzschild spacetime. We find noncommutative form of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Kourosh Nozari , Siamak Akhshabi

The star product technique translates the framework of local fields on noncommutative space-time into nonlocal fields on standard space-time. We consider the example of fields on $\kappa$- deformed Minkowski space, transforming under…

High Energy Physics - Theory · Physics 2016-08-15 P. Kosiński , J. Lukierski , P. Maślanka

Noncommutativity lays hidden in the proofs of classical dynamics. Modern frameworks can be used to bring it to light: *-products, groupoids, q-deformed calculus, etc.

History and Overview · Mathematics 2007-05-23 Alejandro Rivero

Introducing constant background fields into the noncommutative gauge theory, we first obtain a Hermitian fermion Lagrangian which involves a Lorentz violation term, then we generalize it to a new deformed canonical noncommutation relations…

High Energy Physics - Phenomenology · Physics 2015-03-03 Cui-bai Luo , Feng-yao Hou , Zhu-fang Cui , Xiao-jun Liu , Hong-shi Zong

This paper reviews the physics of stars, the type, structure, evolution and stability. Simple thermodynamics and statistical mechanics are used to show the inner working of white dwarf and neutron stars. The major concentration of the paper…

Popular Physics · Physics 2024-03-21 Anuj Chaudhri

Due to the highly degeneracy of electrons in white dwarf stars, we expect that the relativistic effects play very important role in these stars. In the present article, we study the properties of the condensed matter in white dwarfs using…

Solar and Stellar Astrophysics · Physics 2020-03-24 M. I. Nouh , A. S. Saad , M. M. Elkhateeb , B. Korany

We study a Newtonian cosmological model in the context of a noncommutative space. It is shown that the trajectories of a test particle undergo modifications such that it no longer satisfies the cosmological principle. For the case of a…

High Energy Physics - Theory · Physics 2010-11-05 Juan M. Romero , J. A. Santiago

Noncommutative geometry is one of the quantum gravity theories, which various researchers have been using to describe different physical and astrophysical systems. However, so far, no direct observations can justify its existence, and this…

General Relativity and Quantum Cosmology · Physics 2023-01-27 Surajit Kalita , T. R. Govindarajan , Banibrata Mukhopadhyay

The effects of nonlinear oscillations in compact stars are attracting considerable current interest. In order to study such phenomena in the framework of fully nonlinear general relativity, highly accurate numerical studies are required. We…

General Relativity and Quantum Cosmology · Physics 2009-09-24 Michael Gabler , Ulrich Sperhake , Nils Andersson

We consider the consistent deformation of the relativistic quantum mechanics introducing the noncommutativity of the space-time and preserving the Lorentz symmetry. The relativistic wave equation describing the spinning particle on…

High Energy Physics - Theory · Physics 2014-04-21 V. G. Kupriyanov

Composite system is studied in noncommutative phase space with preserved rotational symmetry. We find conditions on the parameters of noncommutativity on which commutation relations for coordinates and momenta of the center-of-mass of…

Quantum Physics · Physics 2018-02-27 Kh. P. Gnatenko , V. M. Tkachuk

We present exact quantum solutions for a noncommutative, multidimensional cosmological model and show that stabilization of extra dimensions sets in with the introduction of noncommutativity between the scale factors. An interpretation is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 N. Khosravi , S. Jalalzadeh , H. R. Sepangi

Neutron stars are usually assumed to be cold; however, in certain dynamical astrophysical scenarios such as newly born neutron stars or binary star mergers, the temperature effects play a non-negligible role. We systematically derive the…

High Energy Astrophysical Phenomena · Physics 2025-05-27 Deepak Kumar , Asit Karan , Anshuman Verma , Hiranmaya Mishra , Ritam Mallick

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

Probing the existence of hypothetical particles beyond the Standard model often deals with extreme parameters: large energies, tiny cross-sections, large time scales, etc. Sometimes laboratory experiments can test required regions of…

High Energy Astrophysical Phenomena · Physics 2021-10-26 P. Tinyakov , M. S. Pshirkov , S. B. Popov

In this work we shall explore the effects of non commutativity in fractional classical and quantum schemes using the flat Friedmmann-Robertson-Walker (FRW) cosmological model coupled to a scalar field in the K-essence formalism. In previous…

General Relativity and Quantum Cosmology · Physics 2024-03-04 J. Socorro , J. Juan Rosales , Leonel Toledo-Sesma