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Thermodynamics of noncommutative geometry inspired black holes based on Maxwell-Boltzmann smeared mass distribution

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Chinese Physics C 2014年第2期38卷 34-39页

作者：梁钧刘艳春朱桥 College of Science Shannxi University of Science and Technology Library Shannxi University of Science and Technology

In order to further explore the efects of non-Gaussian smeared mass distribution on the thermodynamical properties of noncommutative black holes, we consider noncommutative black holes based on Maxwell-Boltzmann smeared mass distribution in（2＋1）-dimensional spacetime. The thermodynamical properties of the black holes are investigated, including Hawking temperature, heat capacity, entropy and free energy. We find that multiple black holes with the same temperature do not exist, while there exists a possible decay of the noncommutative black hole based on Maxwell-Boltzmann smeared mass distribution into the rotating （commutative） BTZ black hole.

关键词： physics of black holes black hole thermodynamics noncommutative geometry

Vacuum Solutions of Classical Gravity on Cyclic Groups from noncommutative geometry

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Communications in Theoretical Physics 2002年第1期37卷 11-14页

作者： DAIJian SONGXing－Chang InstituteofTheoreticalPhysics SchoolofPhysicsPekingUniversityBeijing100871China

Based on the observation that the moduli of a link variable on a cyclic group modify Connes' distance on this group, we construct several action functionals for this link variable within the framework of noncommutative geometry. After solving the equations of motion, we find that one type of action gives nontrivial vacuum solution for gravity on this cyclic group in a broad range of coupling constants and that such a solution can be expressed with Chebyshev's polynomials.

关键词： non-unitary link variable Connes' distance formula vacuum solution noncommutative geometry cyclic group

noncommutative-geometry Wormholes Based on the Casimir Effect

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Journal of High Energy Physics, Gravitation and Cosmology 2023年第1期9卷 295-300页

作者： Peter K. F. Kuhfittig Department of Mathematics Milwaukee School of Engineering Milwaukee WI USA

While wormholes are as good a prediction of Einstein’s theory as black holes, they are subject to severe restrictions from quantum field theory. In particular, holding a wormhole open requires a violation of the null energy condition, calling for the existence of exotic matter. The Casimir effect has shown that this physical requirement can be met on a small scale, thereby solving a key conceptual problem. The Casimir effect does not, however, guarantee that the small-scale violation is sufficient for supporting a macroscopic wormhole. The purpose of this paper is to connect the Casimir effect to noncommutative geometry, which also aims to accommodate small-scale effects, the difference being that these can now be viewed as intrinsic properties of spacetime. As a result, the noncommutative effects can be implemented by modifying only the energy momentum tensor in the Einstein field equations, while leaving the Einstein tensor unchanged. The wormhole can therefore be macroscopic in spite of the small Casimir effect.

关键词： Traversable Wormholes noncommutative geometry Casimir Effect

A note on quantum odometers

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Science China Mathematics 2023年第7期66卷 1555-1568页

作者： Slawomir Klimek Matt McBride J.Wilson Peoples Department of Mathematical Sciences Indiana University-Purdue University IndianapolisIndianapolisIN46202USA Department of Mathematics and Statistics Mississippi State UniversityMississippi StateMS 39762USA Department of Mathematics The Pennsylvania State UniversityUniversity ParkPA 16802USA

We discuss various aspects of noncommutative geometry of smooth subalgebras of Bunce-Deddens-Toeplitz algebras.

关键词： noncommutative geometry derivation smooth subalgebra K-theory

Singularities of noncompact charged objects

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Chinese Physics B 2013年第3期22卷 192-195页

作者： M.Sharif G.Abbas Department of Mathematics University of the PunjabQuaid-e-Azam CampusLahore-54590Pakistan

We formulate a model for noncompact spherical charged objects in the framework of noncommutative field *** Einstein-Maxwell field equations are solved with charged anisotropic *** choose matter and charge densities as functions of the two parameters,instead of defining these quantities in terms of the Gaussian distribution *** is found that the corresponding densities and the Ricci scalar are singular in origin,whereas the metric is nonsingular,indicating a spacelike *** numerical solution of the horizon equation implies that there are two or one or no horizon（s）,depending on the *** also evaluate the Hawking temperature and find that a black hole with two horizons is evaporated to an extremal black hole with one horizon.

关键词： noncommutative geometry electromagnetic field spacetime singularity

One-loop renormalizability of noncommutative U(1) gauge theory with scalar fields

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Chinese Physics B 2010年第1期19卷 111-116页

作者：黄家辉盛正卯 Zhejiang Institute of Modern Physics Department of PhysicsZhejiang University

This paper uses the background field method to calculate one-loop divergent corrections to the gauge field propa- gators in noncommutative U（1） gauge theory with scalar fields. It shows that for a massless scalar field, the gauge field propagators are renormalizable to 02-order, but for a massive scalar field they are renormalizable only to O-order.

关键词： noncommutative geometry quantum field theory renormalization

Connes distance of 2D harmonic oscillators in quantum phase space

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Chinese Physics B 2021年第11期30卷 170-179页

作者： Bing-Sheng Lin Tai-Hua Heng School of Mathematics South China University of TechnologyGuangzhou 510641China Laboratory of Quantum Science and Engineering South China University of TechnologyGuangzhou 510641China School of Physics and Material Science Anhui UniversityHefei 230601China

We study the Connes distance of quantum states of two-dimensional(2D)harmonic oscillators in phase *** the Hilbert–Schmidt operatorial formulation,we construct a boson Fock space and a quantum Hilbert space,and obtain the Dirac operator and a spectral triple corresponding to a four-dimensional(4D)quantum phase *** on the ball condition,we obtain some constraint relations about the optimal *** construct the corresponding optimal elements and then derive the Connes distance between two arbitrary Fock states of 2D quantum harmonic *** prove that these two-dimensional distances satisfy the Pythagoras *** results are significant for the study of geometric structures of noncommutative spaces,and it can also help us to study the physical properties of quantum systems in some kinds of noncommutative spaces.

关键词： Connes distance noncommutative geometry harmonic oscillator

Dirac Neutrino Masses in NCG

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Communications in Theoretical Physics 2001年第4期35卷 441-446页

作者： LIChang－Hui DINGHao－Gang 等 DepartmentofPhysics PekingUniversityBeijing100871China

Several models in noncommutative geometry (NCG) with mild changes to the standard model are introduced to discuss the neutrino mass problem. We use two constraints, Poincaré duality and gauge anomaly free, to discuss the possibility of containing right-handed neutrinos in them. Our work shows that no model in this paper, with each generation containing a right-handed neutrino, can satisfy these two constraints at the same time. So, to consist with neutrino oscillation experiment results, maybe fundamental changes to the present version of NCG are usually needed to include Dirac massive neutrinos.

关键词： neutrino mass noncommutative geometry

Charged noncommutative Wormhole Solutions via Power-Law f(T) Models

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Communications in Theoretical Physics 2016年第10期65卷 411-422页

作者： Shamaila Rani Abdul Jawad M.Bilal Amin Department of Mathematics COMSATS Institute of Information Technology

In this paper,we explore static spherically symmetric charged wormhole solutions in extended teleparallel gravity taking power-law f(T) *** consider noncommutative geometry under Lorentzian *** order to obtain matter components,we develop field equations using effective energy-momentum tensor for non-diagonal *** explore solutions by considering various viable power-law f(T) models,which also include teleparallel gravity *** violation of energy conditions obtain by exotic matter to form wormhole solutions in teleparallel case while,physical acceptable wormhole solutions exist for charged noncommutative wormhole solutions for some cases of power-law *** effective energy-momentum tensor and charge are responsible for the violation of the energy ***,we check the equilibrium condition for these *** equilibrium condition meets for the teleparallel case and some power-law solutions while remaining solutions are either in less equilibrium or in disequilibrium situation.

关键词： f(T) gravity wormhole Lorentzian distribution noncommutative geometry