ANISOTROPIC COMPACT STARS WITH VARIABLE COSMOLOGICAL CONSTANT
نویسندگان
چکیده
منابع مشابه
Strange stars and the cosmological constant problem
The cosmological constant problem represents an evident tension between our present description of gravity and particle physics. Many solutions have been proposed, but experimental tests are always difficult or impossible to perform and present phenomenological investigations focus only on possible relations with the dark energy, that is with the accelerating expansion rate of the contemporary ...
متن کاملField theory models for variable cosmological constant
Anthropic solutions to the cosmological constant problem require seemingly unnatural scalar field potentials with a very small slope or domain walls (branes) with a very small coupling to a four-form field. Here we introduce a class of models in which the smallness of the corresponding parameters can be attributed to a spontaneously broken discrete symmetry. We also demonstrate the equivalence ...
متن کاملCompact embedded hypersurfaces with constant higher order anisotropic mean curvatures
Given a positive function F on S which satisfies a convexity condition, for 1 ≤ r ≤ n, we define the r-th anisotropic mean curvature function H r for hypersurfaces in R which is a generalization of the usual r-th mean curvature function. We prove that a compact embedded hypersurface without boundary in R with H r = constant is the Wulff shape, up to translations and homotheties. In case r = 1, ...
متن کاملSome Bianchi Type I Viscous Fluid Cosmological Models with a Variable Cosmological Constant
Some Bianchi type I viscous fluid cosmological models with a variable cosmological constant are investigated in which the expansion is considered only in two direction i.e. one of the Hubble parameter (H1 = A4 A ) is zero. The viscosity coefficient of bulk viscous fluid is assumed to be a power function of mass density whereas the coefficient of shear viscosity is considered as constant in firs...
متن کاملNonstandard Cosmology With Constant and Variable Gravitational and Variable Cosmological “Constants” and Bulk Viscosity
We have analyzed a nonsingular model with a variable cosmological term following the Carvalho et al. ansatz. The model was shown to approximate to the model of Freese et al. in one direction and to the Özer-Taha in the other. We have then included the effect of viscosity in this cosmology, as this effect has not been considered before. The analysis showed that this viscous effect could be impor...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Journal of Modern Physics D
سال: 2012
ISSN: 0218-2718,1793-6594
DOI: 10.1142/s0218271812500885