Diffusion coefficients and constraints on hadronic inhomogeneities in the early universe Sovan Sau, Sayantan Bhattacharya and Soma Sanyal Eur. Phys. J. C, 79 5 (2019) 439 Published online: 24 May 2019 DOI: 10.1140/epjc/s10052-019-6938-6