Quantal distribution functions in non-extensive statistics and an early universe test revisited

Within the context of nonextensive thermostatistics, we use the factorization approximation to study a recently proposed early universe test. A very restrictive bound upon the non-extensive parameter is presented: \q - 1\ < 4.01 x 10(-3). This new result is found to be very close to the existing bound which was obtained from the asymptotic approach of Tsallis et al. (C) 1999 Elsevier Science B.V. All rights reserved.