Study of Particle Creation with Quadratic Equation of State in Higher Derivative Theory
- PDF / 1,307,047 Bytes
- 19 Pages / 595.224 x 790.955 pts Page_size
- 16 Downloads / 158 Views
PARTICLES AND FIELDS
Study of Particle Creation with Quadratic Equation of State in Higher Derivative Theory G. P. Singh1
· Ashwini R. Lalke1 · Nikhil Hulke2
Received: 8 March 2020 © Sociedade Brasileira de F´ısica 2020
Abstract We investigate the effect of particle creation in flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime under the higher derivative theory composition. The exact solution of the field equation in higher derivative theory is obtained by considering the quadratic equation of state, p = ωρ 2 − ρ and different forms of deceleration parameter. The physical acceptance and stability of the models are explored by discussing energy conditions and squared sound speed. In addition to that, the statefinder diagnostic pair {r, s} is also scrutinized to measure the deviation of considered models from cold dark matter (CDM) model. Keywords Higher derivative theory · FLRW spacetime · Particle creation · Quadratic equation of state
1 Introduction Currently, our universe is in an accelerating phase [1] and an explanation for this acceleration is set forth by dark energy (DE). In fundamental physics, DE has probably been considered as the most ambitious and tantalizing field of research, which is also called “The Mystery of the Millennium” [2] laid down by Riess and Perlmutter along with their respective collaborators [1, 3, 4]. There is a long history of modifying Einstein’s general theory of relativity (GTR). Einstein himself [5] modified the gravitational field equation by adding cosmological constant, perhaps the first modification. Post that, many modifications have been made, focusing on both ultraviolet and infrared limits of Einstein’s field equation [6–8].
G. P. Singh
[email protected]; [email protected] Ashwini R. Lalke [email protected] Nikhil Hulke [email protected] 1
Department of Mathematics, Visvesvaraya National Institute of Technology, Nagpur, India
2
Department of Applied Mathematics, Shri Ramdeobaba College of Engineering and Management, Nagpur, India
Several theories have been initiated in the past in the literature, including the addition of some extra fields viz. scalar, vector, tensor field [9] to the Einstein’s theory, enriching the gravitational action by introducing higherorder derivative theories [10], Weyl-Cartan theories [11, 12], and massive gravity theories [13, 14]. There are various attempts to modify Einstein’s GTR; one is by adding a curvature squared term in EinsteinHilbert action, known as the generalized theory of gravity. The curvature squared term plays an integral part in addition to the Einstein action in the early epoch. By adding a suitable counter term R 2 to Einstein action, we can get a well-behaved perturbation theory. Higher-order theories of gravity admit inflation, which was proposed by Starobinsky [15] in 1980. Nevertheless, the theory got its popularity only after Guth’s study [16] in 1981, where a temperature phase transition mechanism is used by him. The particle creation mechanism was pioneered by Schrodinger [17], f
Data Loading...
