Thermodynamics of flat FLRW universe in Rastall Theory

Understand

In this paper, after referring to the Rastall theory, we address some of its cosmological consequences.

• Moreover, bearing the Clausius relation in mind, using Friedman equations in Rastall theory and the Cai-Kim temperature, we obtain a relation for the apparent horizon entropy of a flat FLRW universe.
• In addition, we impose the entropy positivity condition on the obtained relation for the horizon entropy, to find some constraints on the Rastall parameters.
• Moreover, we investigate the second and generalized second laws of thermodynamics.