University of New South Wales

Title: Do fundamental constants of nature vary with time and distance ?

Abstract:
Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant alpha=e^2/hc could be detected via shifts in frequencies of atomic transitions in quasar (QSO) absorption systems. We have developed a new approach which improves the sensitivity of this method 30 times. It also provides much better control of systematic errors. We studied three independent samples of data contaning 130 absorption systems spread from 2 to 10 billion years after Big Bang. All three data samples hint that alpha was smaller in the past (8-11 billion years ago).

We also derive limits on variation of strong interaction, quark masses and gravity from (i) Big Bang Nucleosynthesis; (ii) Oklo natural nuclear reactor (iii) atomic clocks.

Phys. Rev. Lett. 82,888,1999;82,884,1999;87,091301,2001; astro-ph, 2002.