[PDF] Top 20 Polytropic Bulk Viscous Cosmological Model with Variable G and Λ

... with polytropic bulk viscous ...of bulk viscosity in the cosmic evolution, especially as its early stages seems to be significant ...ρ, cosmological constant Λ, expansion scalar ... See full document

... simplest model of the observed universe is well rep- resented by Friedmann-Robertson-Walker (FRW) mod- els, which are both spatially homogeneous and ...constructing cosmological models suitable for ... See full document

... of cosmological models of un- iverse. The cosmological term Λ has been introduced in 1917 by Einstein to modify his own equation of general ...this Λ-term remains a focal point of interest in ... See full document

... varying G has many interesting consequences in ...that G-varying cosmology is consistent with what so ever cosmological observations available at ...gives G and Λ as coupled fields ... See full document

... = Λ where c is the speed of light and G is the gravitational ...static model of the universe, Einstein might have been able to predict the expansion of the universe or the universe is in a dynamic ... See full document

... fluid cosmological models with time varying gravitational and cosmological ...a viscous fluid with time-de- pendent G ...the bulk viscosity coeffi- cient is a power function of the ... See full document

... of cosmological models are presented with variable deceleration parameter q and cosmological term  in spatially homogeneous and anisotropic Bianchi type-I space-time in presence of bulk and ... See full document

... literature cosmological models with a constant deceleration parameter have been studied by Berman and Gomide (1988), Johri and Desikan (1994), Singh and Desikan (1997), Maharaj and Naidoo (1993), Pradhan et ...the ... See full document

... Barber has proposed two theories well known as self creation theories. First theory is the modification of Brans Dicke theory [1] in which Barber has included continuous creation of matter. The universe is seen to be ... See full document

... a bulk viscous cosmic fluid, in the presence of variable gravitational and cosmological ...with bulk viscosity, gravitational and cosmological constants have been ...of ... See full document

... I bulk viscous barotropic fluid cosmological model with varying Λ and functional relation on Hubble parameter in self-creation theory of ...our model may have more than three ... See full document

... of cosmological models with dark energy create much more interest due to the fact that our universe is undergoing an accelerated expansion which is driven by an exotic energy with large negative pressure named ... See full document

... A cosmological model containing a global magnetic field is necessarily ...of cosmological origin have been discussed by Asseo and Sol 15 , and Madsen 16 ...the cosmological models with magnetic ... See full document

... w indicates the non-rotating nature of the universe. The deceleration parameter (q) is grater than zero shows that the spatial volume decreases uniformly with ‘𝑡’ and ultimately the universe may collapse at some time. ... See full document

... Eigenfrequencies of the lowest three modes of a nonrotating and a rotating general-relativistic polytropic model with polytropic index n = 2.5 , and polytropic constant and Keplerian ang[r] ... See full document

... Initially the model has a point type singularity, gravitational constant G t is decreasing and cosmological constant  is infinite at this time when time increases  decrease.The model a[r] ... See full document

... In this paper, the acoustical properties of double poros- ity granular materials, i.e., packings of porous particles, are investigated both theoretically and experimentally. The pa- per is organized as follows. In Sec. ... See full document

... the model has a point type singularity at the initial ...the model approachesisotropy for large value t. Our model satisfies all conditions of homogeneity and isotropization according to the formal ... See full document

... universe model by taking a power-law model for bulk viscosity coe ffi ...power-law model of bulk viscosity appears as an e ↵ ective ingredient to enhance the stability of the respective ... See full document

... The equilibrium stellar models have been built by many au- thors e.g. [1, 6–8]. The first stellar models before the age of computers were polytropic models [9]. The polytropic mod- els provided pretty good ... See full document