Interacting realization of cosmological singularities with variable vacuum energy

LUIS P. CHIMENTO AND MARTIN G. RICHARTE

PHYSICAL REVIEW D - PARTICLE AND FILDS

American Physical Society

Lugar: Maryland; Año: 2015 vol. D92 p. 1 - 11

0556-2821

We examine an interacting dark matter?variable vacuum energy model for a spatially flatFriedmann-Roberston-Walker spacetime, focusing on the appearance of cosmological singularitiessuch as big rip, big brake, big freeze, and big separation along with abrupt events (infinite γ-singularity and new w-singularity) at late times. We introduce a phenomenological interactionwhich has a nonlinear dependence on the total energy density of the dark sector and its derivative,solve exactly the source equation for the model and find the energy density as function of thescale factor as well as the time dependence of the approximate scale factor in the neighborhoodof the singularities. We describe the main characteristics of these singularities by exploringthe type of interaction that makes them possible along with behavior of dark components nearthem. We apply the geometric Tipler and Kr´olak method for determining the fate of timelikegeodesic curves around the singularities. We also explore the strength of them by analyzingthe leading term in some geometric invariants such as the square Riemann scalar and the Ricci scalar