Particle production in higher derivative theory

Singh, G. P.; Беешам, Ароонкумар; Deshpande, Revati

doi:10.1007/s12043-000-0118-x

Cited by 12 publications

(11 citation statements)

References 19 publications

(14 reference statements)

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“…Finally, the time-dependent of the scalar field pressure can be extracted from (12), using (24) and (25), as…”

Section: Solution Of the Field Equationsmentioning

confidence: 99%

“…Cosmological models with perfect fluid as a source matter in HD theory have been studied by several authors [17][18][19][20][21][22][23][24][25][26][27][28] in order to obtain viable cosmological scenario of the early universe. However, in the early universe a number of processes might have occurred leading to a deviation from perfect fluid assumption, e.g., scalar field which is to be taken into account.…”

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confidence: 99%

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Power-Law Expansion and Scalar Field Cosmology in Higher Derivative Theory

Singh

2012

Int J Theor Phys

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In this paper we study the evolution of a flat Friedmann-Robertson-Walker model filled with a perfect fluid and a scalar field minimally coupled to gravity in higher derivative theory of gravitation. Exact solution of the field equations are obtained by the assumption of power-law form of the scale factor. A number of evolutionary phases of the universe including the present accelerating phase are found to exist with scalar field in the higher derivative theory of gravitation. The properties of scalar field and other physical parameters are discussed in detail. We find that the equation of state parameter for matter and scalar field are same at late time in each case. We observe that a higher derivative term can hardly be a candidate to describe the presently observed accelerated expansion. It is only the hypothetical fluids, which provide the late time acceleration. It is also remarkable that the higher derivative theory does not effect the radiating model of scalar field cosmology.

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“…Finally, the time-dependent of the scalar field pressure can be extracted from (12), using (24) and (25), as…”

Section: Solution Of the Field Equationsmentioning

confidence: 99%

mentioning

confidence: 99%

Power-Law Expansion and Scalar Field Cosmology in Higher Derivative Theory

Singh

2012

Int J Theor Phys

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“…Note that matter creation is being actively investigated in cosmological literature, see e.g. [31][32][33][34][35][36]. If mass non-conservation is to occur in "cosmological" conditions, it must exist in nature, and so possibly (in minute, not yet observable quantities) in today's world.…”

Section: Equations Of Motion and Matter Production For A Perfect mentioning

confidence: 99%

Space isotropy and weak equivalence principle in a scalar theory of gravity

Arminjon¹

2006

Braz. J. Phys.

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We consider a preferred-frame bimetric theory in which the scalar gravitational field both influences the metric and has direct dynamical effects. A modified version ("v2") is built, by assuming now a locally-isotropic dilation of physically measured distances, as compared with distances evaluated with the Euclidean space metric. The dynamical equations stay unchanged: they are based on a consistent formulation of Newton's second law in a curved space-time. To obtain a local conservation equation for energy with the new metric, the equation for the scalar field is modified: now its l.h.s. is the flat wave operator. Fluid dynamics is formulated and the asymptotic scheme of post-Newtonian approximation is adapted to v2. The latter also explains the gravitational effects on light rays, as did the former version (v1). The violation of the weak equivalence principle found for gravitationally-active bodies at the point-particle limit, which discarded v1, is proved to not exist in v2. Thus that violation was indeed due to the anisotropy of the space metric assumed in v1.

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“…Singh and Beesham [33], Singh et al [34] studied cosmological models having bulk viscosity and particle creation within the frame work of Brans-Dicke theory. Singh et al [35] have also studied the effect of particle production in higher derivative theory.…”

Section: Introductionmentioning

confidence: 99%

Bianchi Type I Cosmological Models with Expansion Driven by Particle Creation

Desikan¹

2018

Preprint

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A study of Bianchi Type I cosmological model is undertaken in the framework of creation of particles. To accommodate the creation of new particles, the universe is regarded as an Open thermodynamical system. The energy conservation equation is modified with the incorporation of a creation pressure in the energy momentum tensor. Exact solutions of the field equations are obtained (i) for a particular choice of the particle creation function and (ii) by considering the deceleration parameter to be constant. In the first model the behavior of the solution at late times is investigated. The physical aspects of the model have also been discussed. In the case of the second model we have restricted our analysis to the power law behaviour for the average scale factor. This leads to a particular form for the particle creation function. The behavior of the solution is investigated and the physical aspects of the model have also been discussed for the matter dominated era.

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Particle production in higher derivative theory

Cited by 12 publications

References 19 publications

Power-Law Expansion and Scalar Field Cosmology in Higher Derivative Theory

Power-Law Expansion and Scalar Field Cosmology in Higher Derivative Theory

Space isotropy and weak equivalence principle in a scalar theory of gravity

Bianchi Type I Cosmological Models with Expansion Driven by Particle Creation

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