Can an interacting varying Chaplygin gas and tachyonic matter accelerate universe?

Abstract

In this paper, a cosmological model involving interacting varying Chaplygin gas of a specific type and a tachyonic matter is considered to address the problem known as the accelerated expansion of the universe. The study shows that a specific form of the potential and appropriate values of the parameters allows a transition from early tachyonic to late-time tachyonic dark matter with [Formula: see text]. This point, up to our knowledge, makes the considered cosmological scenario unique in the literature. Moreover, discussion on future finite-time singularities for the considered models finalizes the paper. The study shows that in case of non-interacting model, the fate of universe will be either Type II (The Sudden Singularity), or Type IV (“Generalized Sudden Singularity”) singularity. On the other hand, the consideration of [Formula: see text] non-gravitational interaction in addition to Type II and Type IV singularities will induce also Type V (“[Formula: see text]-singularity”) singularity, while with [Formula: see text] only Type IV singularity will be observed. Moreover, two forms of scale factor have been considered allowing to analytically obtain the behavior of the cosmological parameters without specifying an explicit form of the potential for tachyonic matter.