Rotational perturbations of cosmological viscous-fluid Universe with zero-mass scalar field

1987 ◽  
Vol 139 (1) ◽  
pp. 183-193 ◽  
Author(s):  
Koijam Manihar Singh
Keyword(s):  
Scalar Field ◽  
Viscous Fluid ◽  
Zero Mass

Causal viscous universe coupled with zero-mass scalar field in higher derivative theory

2011 ◽  
Vol 334 (1) ◽  
pp. 187-191 ◽  
Author(s):  
N. Ibotombi Singh ◽  
S. Surendra Singh ◽  
S. Romaleima Devi
Keyword(s):  
Scalar Field ◽  
Zero Mass ◽  
Higher Derivative

scholarly journals Brans - Dicke Cosmology with Causal Viscous Fluid

1996 ◽  
Vol 49 (5) ◽  
pp. 899 ◽  
Author(s):  
N Banerjee ◽  
A Beesham
Keyword(s):  
Scalar Field ◽  
Cosmological Model ◽  
Viscous Fluid ◽  
Exact Solutions ◽  
Power Function ◽  
Causal Theory ◽  
Scale Factor ◽  
Scalar Tensor Theory ◽  
Equilibrium Thermodynamics ◽  
Tensor Theory

Exact solutions for the spatially flat (k = 0) Robertson–Walker cosmological model in Brans–Dicke scalar tensor theory have been obtained in the presence of a causal viscous fluid. It is found that if the scale factor is a power function of the scalar field, then solutions can be obtained in the full causal theory but not in the truncated theory of non-equilibrium thermodynamics.

Hamiltonian Formalism of Bianchi Type I Model for Fluid Bulk and Shearing Viscosity

2021 ◽  
Author(s):  
Shouvik Sadhukhan ◽  
Alokananda Kar
Keyword(s):  
Scalar Field ◽  
Viscous Fluid ◽  
Bianchi Type ◽  
Hamiltonian Formalism ◽  
Big Bang ◽  
Type I ◽  
Scale Factors ◽  
Anisotropic Expansion ◽  
Large Anisotropy

In this paper we will consider the cosmic fluid to be dissipating i.e it has both bulk and shearing viscosity. We propose the Hamiltonian formalism of Bianchi type 1 cosmological model for cosmic fluid which is dissipating i.e it has both shearing and bulk viscosity. We have considered both the equation of state parameter ω and the cosmological constant Λ as the function of volume V(t) which is defined by the product of three scale factors of the Bianchi type 1 line element. We propose a Lagrangian for the anisotropic Bianchi type-1 model in view of a variable mass moving in a variable potential . We can decompose the anisotropic expansion of Bianchi type 1 in terms of expansion and shearing motion by Lagrangian mechanism. We have considered a canonical transformation from expanding scale factor to scalar field ø which helps us to give the proper classical definition of that scalar field in terms of scale factors of the mentioned model. By this transformation we can express the mass to be moving in a scalar potential field. This definition helps us to explain the nature of expansion of universe during cosmological inflation. We have used large anisotropy(as in the cases of Bianchi models) and proved that cosmic inflation is not possible in such large anisotropy. Therefore we can conclude that the extent of anisotropy is less in case of our universe. Otherwise the inflation theory which explained the limitations of Big Bang cannot be resolved. In the case of bulk and shearing viscous fluid we get the solution of damped harmonic oscillator after the cosmological inflation.Part I contains the calculations of bulk viscous fluids and Part II contains the calculations of bulk and shearing viscous fluid.At the end we have also provided the relation of shearing and expansion.Part III will give the approximation of low viscosity to solve the viscous fluid problem.

Gravitational repulsion in the Einstein-zero-mass scalar theory

1984 ◽  
Vol 62 (7) ◽  
pp. 629-631 ◽  
Author(s):  
K. D. Krori ◽  
J. C. Sarmah ◽  
D. Goswami
Keyword(s):  
Scalar Field ◽  
Recent Work ◽  
Scalar Theory ◽  
Zero Mass ◽  
Gravitational Repulsion ◽  
Particle Velocities

In this paper we extend a recent work by McGruder by investigating gravitational repulsion in the Einstein-zero-mass scalar theory. We notice that in the presence of a scalar field, gravitational repulsion is possible for particle velocities lower than those required in the pure Einstein (Schwarzschild) field. The zero-mass scalar field has acquired particular importance recently because of a suggestion by Weinberg and Wilczek that there should exist a pseudoscalar boson, the so-called axion, of negligible mass. The work of Peccei and Quinn has lent further support to the idea of axions.

Viscous fluid universe interacting with scalar field

1987 ◽  
Vol 26 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Koijam Manihar Singh ◽  
K. S. Bhamra
Keyword(s):  
Scalar Field ◽  
Viscous Fluid
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