Primordial black hole formation from inflaton

Measurements of the distances to SNe Is have produced strong evidence that the expansion of the Universe is really accelarating, implying the existenc e of a nearly uniform component of dark energy with the simplest explanatio n as a cosmological constant. In this paper a small changing cosmological t erm is proposed, which is a function of a slow-rolling scalar field, by whi ch the de Sitter primordial black holes' properties, for both charged and u ncharged cases, are carefully examined and the relationship between the bla ck hole formation and the energy transfer of the inflaton is eluciated. The criterion for primordial black hole formation is given.