General relativistic energy conditions: The Hubble expansion in the epoch of galaxy formation

摘要: The energy conditions of Einstein gravity (classical general relativity) are designed to extract as much information possible from classical relativity without enforcing a particular equation state for the stress energy. This systematic avoidance need specify is particularly useful in cosmological setting {emdash} since fluid Friedmann-Robertson-Walker-type universe extremely uncertain. I shall show that provide simple and robust bounds on behavior both density look-back time function redshift. current observations {ital suggest} so-called strong condition} (SEC) violated at some between epoch galaxy formation present. implies no combination {open_quotes}normal{close_quotes}} matter capable fitting observational data. {copyright} 1997} American Physical Society}