On double brackets for marked surfaces
摘要
We propose a construction of a double quasi-Poisson bracket on the group algebra associated to the twisted fundamental group of a marked oriented surface (S, P) with boundary, where P is a finite set of marked points on the boundary of the surface S such that on every boundary component there is at least one point of P. We show that this double bracket is a noncommutative generalization of the well-known Goldman bracket, defined on the space of free homotopy classes of loops on S. For an algebra A without polynomial identities, we construct a double bracket on the space of decorated twisted