Finite temperature effects on cosmological baryon diffusion and inhomogeneous Big-Bang nucleosynthesis

We have studied finite temperature corrections to the baryon transport cross sections and diffusion coefficients. These corrections are based upon recently computed renormalized electron mass and modified density of states due to the background thermal bath. It is found that the optimum nucleosynthesis yields computed using our diffusion coefficients shift to longer distance scales by a factor of about 3. We also found that the minimum value of $^4 He$ abundance decreases by $\Delta Y_p \simeq 0.01$. Effects of these results on constraints from primordial nucleosynthesis are discussed.