On a time dependence of physical constants
Varshalovich D. A. , Levshakov S. A.
Analysis of the wavelengths of lines of molecular hydrogen observed in the spectrum of the quasar PKS 0528-250 yields an estimate of an upper limit on a hypothetical change in the ratio of the electron mass to the proton mass, /z = /?2e/wpt at a cosmological time scale. This upper limit on the rate of change of μ is \μ/μ\ <3χ 10~13 yr~l. This is two orders of magnitude lower than the value μ/μ — (2.3±0.3) X 10~n yr_I found from laboratory measurements [Yu. S. Domnin et aly JETP Lett 43, 212 (1986)].