The Hayward metric is the simplest description of a
black hole which is
non-singular. The metric was written down by Sean Hayward as the minimal model which is regular, static,
spherically symmetric and
asymptotically flat.[1] The metric is not derived from any particular
alternative theory of gravity, but provides a framework to test the formation and evaporation of non-singular black holes both within
general relativity and beyond. Hayward first published his metric in 2005 and numerous papers have studied it since.[2][3][4][5]