State equations for massless spin fields in static spherical spacetime filled with quintessence

The entropy density, energy density, pressure and equation of state for the gases of massless particles with spin s ≤ 2 around the static spherical black hole with quintessence are investigated by using the brick-wall method. It is shown that the state equations for spin fields in curved spacetime do not take the same forms as that in flat spacetime and contain additional terms with spin dependence. Then the character of the terms and the effect of quintessence and spin on them are discussed.