Singularities of noncompact charged objects  

作　　者：M.Sharif G.Abbas 

机构地区：[1]Department of Mathematics,University of the Punjab,Quaid-e-Azam Campus,Lahore-54590,Pakistan

出　　处：《Chinese Physics B》2013年第3期192-195,共4页中国物理B（英文版）

基　　金：Project supported by the Higher Education Commission of Pakistan through the Indigenous Ph.D. 5000 Fellowship Program Batch-IV

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

分 类 号：O314[理学—一般力学与力学基础]