Dynamical systems analysis of a cosmological model with interacting Umami Chaplygin fluid in adiabatic particle creation mechanism: some bouncing features

Abstract

The present work aims to investigate an interacting Umami Chaplygin gas (UCG) in the background dynamics of a spatially flat Friedmann–Lemaitre–Robertson–Walker Universe when adiabatic particle creation is allowed. Here, the Universe is taken to be an open thermodynamical model where the particle is created irreversibly and consequently, the creation pressure comes into the energy-momentum tensor of the material content. The particle creation rate is assumed to have a linear relationship with the Hubble parameter ( ) and the created particle is dark matter (pressureless). With this creation rate a single fluid model studied and found no phase transition. Then, we studied an interacting two-fluid model where second fluid is taken as perfect fluid equation of state (EOS) and late-time acceleration is obtained. Next, interacting UCG is studied in context of particle creation. Dynamical stability of the model is performed by perturbing the autonomous system around critical points upto first order. Classical stability of the model is also studied at each critical point. This study explores some cosmologically viable scenarios when we constrain the model parameters. Some critical points exhibit the accelerated de Sitter expansion of the Universe at both the early phase as well as the late phase of evolution which is characterized by completely Umami Chaplygin fluid EOS. Scaling solutions are also described by some other critical points showing late-time accelerated attractors in phase space satisfying present observational data, and solving the coincidence problem. In a specific region of parameters, a sequence of critical points is achieved exhibiting a unified cosmic evolution of the Universe starting from early inflation (represented by source point), which is followed by a decelerated intermediate phase (described by saddle solution), and finally goes through the late-time dark energy dominated Universe (represented by stable point). Finally, non-singular bouncing behavior of the Universe is also investigated for this model numerically.