Astrophysical Limits on the Evolution of Dimensionless Physical Constants over Cosmological Time

Abstract

We report new upper limits on any possible long-term time variation of the ratio of the electron to proton masses, $(m_e/m_p)$, the fine-structure constant, ($\alpha$), and the quantity ${\alpha }^2{g}_p(m_e/m_p)$, where $g_p$ is the proton gyromagnetic ratio. These limits are based on extremely high precision observations of H${}_2$, Si${}^{3+}$, C${}^0$ and H${}^0$ in high-redshift quasar absorption lines. They amount to 95\% confidence ranges of $(-7.6\to 9.7)\times 10^{-14}$ yr${}^{-1}$ for ($m_e/m_p$), $(-4.6\to 4.2)\times 10^{-14}$ yr${}^{-1}$ for $\alpha$\ and $(-2.2\to 4.2)\times 10^{-15}$ yr${}^{-1}$ for ${\alpha }^2{g}_p(m_e/m_p)$, where the elapsed time has been computed for a cosmology with \hnought = 75 km s${}^{-1}$ Mpc${}^{-1}$ and \qnought = 0.5.

Comments: 10 pages (w/ 2 tables) of text as 1 LaTeX file (aastex style macros: aaspp.sty, flushrt.sty) plus 1 uuencoded compressed tar file of 2 PostScript figures. To appear in the November 10, 1995 Astrophysical Journal