https://doi.org/10.1140/epjc/s10052-019-6627-5
Regular Article - Theoretical Physics
Two-fluid solutions of particle-creation cosmologies
1
Department of Mathematics, Presidency University, 86/1 College Street, Kolkata, 700073, India
2
DAMTP, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Rd., Cambridge, CB3 0WA, UK
3
Instituto de Ciencias Físicas y Matemáticas, Universidad Austral de Chile, Valdivia, Chile
4
Institute of Systems Science, Durban University of Technology, PO Box 1334, Durban, 4000, Republic of South Africa
* e-mail: anpaliat@phys.uoa.gr
Received:
13
December
2018
Accepted:
24
January
2019
Published online:
6
February
2019
Cosmological evolution driven incorporating continuous particle creation by the time-varying gravitational field is investigated. We consider a spatially flat, homogeneous and isotropic universe with two matter fluids in the context of general relativity. One fluid is endowed with gravitationally induced “adiabatic” particle creation, while the second fluid simply satisfies the conservation of energy. We show that the dynamics of the two fluids is entirely controlled by a single nonlinear differential equation involving the particle creation rate, 
. We consider a very general particle creation rate, 
, that reduces to several special cases of cosmological interest, including 
constant, 
(
), 
. Finally, we present singular algebraic solutions of the gravitational field equations for the two-fluid particle creation models and discuss their stability.
© The Author(s), 2019
