Cosmology and short-distance gravity

Abstract

If the observed dark-energy density [Formula: see text] is interpreted as the net contribution of the energy density of the vacuum, [Formula: see text], and the corresponding vacuum length scale [Formula: see text] as the cutoff scale controlling the low-energy, effective field-theory limit of gravity, it follows that the conventional cosmological scenario based on the effective gravitational equations may be valid only up to the TeV energy scale. Such a possibility would be strongly disfavored by the existence of a relic background of primordial gravitational radiation of intensity compatible with present (or near future) experimental sensitivities.