ASTROPHYSICAL LIMITS ON THE EVOLUTION OF DIMENSIONLESS PHYSICAL CONSTANTS OVER COSMOLOGICAL TIME

摘要

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, α, and the quantity α~2g_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 → 9.7) x 10~(14) yr~(-1) for m_e/m_p, (-4.6 → 4.2) x 10~(14) yr~(-1) for α, and (-2.2 → 4.2) x 10~(15) yr~(-1) for α~2g_p(m_e/m_p), where the elapsed time has been computed for a cosmology with H_0 = 75 km s~(-1) Mpc~(-1) and q_0 = 0.5.