On phantom thermodynamics

摘要: Abstract The thermodynamic properties of dark energy fluids described by an equation state parameter ω = p / ρ are rediscussed in the context FRW type geometries. Contrarily to previous claims, it is argued here that phantom regime − 1 not physically possible since both temperature and entropy every physical must be always positive definite. This means one cannot appeal negative order save hypothesis as has been recently done literature. Such a result remains true long chemical potential zero. However, if fluid endowed with non-null potential, field becomes thermodynamically consistent, is, there macroscopic equilibrium states T > 0 S course Universe expansion.