Date: Friday 4 February 2011, 4:30pm Location: Hempfield High School, Room 213 Speaker: Ron Umble, Millersville University Title: Tensor products of A-infinty algebras with homotopy inner products (Joint work with Thomas Tradler) Abstract. The combinatorial structure of an A-infinity algebra with homotopy inner products is controlled by a family of contractible polytopes called pairahedra. In this talk we construct an explicit combinatorial diagonal on the pairahedra and use it to define a tensor product of A-infinity algebras with homotopy inner products. Homotopy inner products appear in actions on moduli spaces and symplectic structures on formal non-commutative supermanifolds.