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<4.01×10−3. This new result is found to be very close to the existing bound which was obtained from the asymptotic approach of Tsallis et al.