Energy conditions and galaxy formation

Abstract

This note summarizes a model-independent analysis of the age of the universe problem that trades off precision in favour of robustness: The energy conditions of Einstein gravity are designed to extract as much information as possible from classical general relativity without specifying a particular equation of state. This is particularly useful in a cosmological setting, where the equation of state for the cosmological fluid is extremely uncertain. The strong energy condition (SEC) provides a simple and robust bound on the behaviour of the look-back time as a function of red-shift. Observation suggests that the SEC may be violated sometime between the epoch of galaxy formation and the present.

Three pages, uses mprocl.sty To appear in the proceedings of the Eighth Marcel Grossmann Conference on General Relativity. (Jerusalem, Israel, June 1997) [Minor typo fixed in references.]