Comment on ‘‘Time variation of fundamental constants, primordial nucleosynthesis, and the size of extra dimensions.’’

It is pointed out that the constraints on the mean radius of the extra dimensions at the time of primordial nucleosynthesis obtained by Kolb, Perry, and Walker get modified if primordial neutrinos are degenerate. Similarly, the constraints on the neutrino degeneracy parameters obtained from primordial nucleosynthesis also change if the volume of the extra dimensions at the time of nucleosynthesis is different than its present value.