Non-zero torsion and late cosmology
Miguel Cruz (Facultad de Física, Universidad Veracruzana, Xalapa, Veracruz, 91000, México); Fernando Izaurieta (Departamento de Física, Universidad de Concepción, Casilla 160, Concepción, 4070105, Chile); Samuel Lepe (Instituto de Física, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av. Brasil 2950, Valparaíso, Chile)
In this work, we study some thermodynamical aspects associated with torsion in a flat FLRW spacetime cosmic evolution. By implementing two Ansatze for the torsion term, we find that the model admits a phantom regime or a quintessence behavior. This scheme differs from the $$\Lambda $$ CDM model at the thermodynamical level. The resulting cosmic expansion is not adiabatic, the fulfillment of the second law of thermodynamics requires a positive torsion term, and the temperature of the cosmic fluid is always positive. The entropy of the torsion phantom scenario is negative, but introducing chemical potential solves this issue. For a Dirac-Milne type Universe, the torsion leads to a growing behavior for the temperature of the fluid but has no incidence on the rate of expansion.