Narrow Results

In this paper, a braneworld model with a perfect fluid on brane and a scalar field on bulk has been used to study quark–hadron phase transition. The bulk scalar field has an interaction with brane matter. This interaction comes into nonconservation relation which describes an energy transfer between bulk and brane. Since quark–hadron transition truly depends on the form of evolution equations, modification of energy conservation equation and Friedmann equation gives rise to some interesting results about the time of transition. The evolution of physical quantities relevant to the quantitative of early times namely energy density ρ, temperature T and scale factor a have been considered utilizing two formalism, crossover formalism and first-order phase transition formalism. The results show that the quark–hadron phase transition occurred about a nanosecond after big bang and the general behavior temperature is similar in both of two formalism.

The slow-roll inflation scenario is studied in the frame of the scalar–tensor theory of gravity, where the scalar field has a nonminimal coupling to the geometric part. After deriving the main dynamical and observable parameter, the consistency of the model with data is considered and we could determine the constants of the model. Then, using the result, the swampland criteria are studied and it is revealed that they are perfectly satisfied. Finally, reheating phase is considered and it is found that the reheating phase lasts for a few e-fold of expansion, and the universe warms up to a high temperature.