Regular Article - Theoretical Physics
Constant curvature f(R) gravity minimally coupled with Yang–Mills field
Department of Physics, Eastern Mediterranean University, G. Magusa, North Cyprus, Mersin 10, Turkey
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Revised: 3 March 2012
Published online: 28 March 2012
We consider the particular class of f(R) gravities minimally coupled with Yang–Mills (YM) field in which the Ricci scalar =R 0=constant in all dimensions d≥4. Even in this restricted class the spacetime has unlimited scopes determined by an equation of state of the form P eff=ωρ. Depending on the distance from the origin (or horizon of a black hole) the state function ω(r) takes different values. It is observed that (the ultra relativistic case in 4 dimensions) and ω→−1 (the cosmological constant) are the limiting values of our state function ω(r) in a spacetime centered by a black hole. This suggests that having a constant ω throughout spacetime around a charged black hole in f(R) gravity with constant scalar curvature is a myth.
© Springer-Verlag / Società Italiana di Fisica, 2012