Particle creation in a f(R) theory with cosmological constraints

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In this paper we study the creation of super-massive real scalar particles in the framework of a f (R) = R - beta/R-n modified gravity theory, with parameters constrained by observational data. The analysis is restrict to a homogeneous and isotropic flat and radiation dominated universe. We compare the results to the standard Einstein gravity with cosmological constant (Lambda CDM model), and we show that the total number density of created particles in the f (R) model is very close to the standard case. Another interesting result is that the spectrum of created particles is beta independent at early times.