“…The optimal L 2 extension theorem (Theorem 1.4 [21]) gives unified optimal estimate versions of various well-known L 2 extension theorems in [39,35,10,52,44,4,38,16], etc. Some interesting relations between the optimal L 2 extension and some questions are found, so that the questions are solved in [21] by using optimal L 2 extension (Theorem 1.4), such as Suita's conjecture (see [57] [45]), L-conjecture (see [59]), extended Suita conjecture (see [59]), and an open question posed by Ohsawa (see [42]), etc.…”