$L_{\infty}$-algebra of an unobstructed deformation functor

Abstract

This is a comment on the Kuranishi method of constructing analytic deformation spaces. It is based on a simple observation that the Kuranishi map can always be inverted in the category of $L_{\infty}$-algebras. The $L_{\infty}$-structure obtained by this inversion is used to define an ''unobstructed'' deformation functor which is always representable by a smooth pointed moduli space. The singular nature of the original Kuranishi deformation space emerges in this setting merely as a result of the truncation of this ``naive'' $L_{\infty}$-algebra controlling the deformations to a usual differential Lie algebra.