20 May 2025, 14:00 CET. Talk by David Martínez Torres.
Abstract: We discuss two dual canonical operations on Dirac structures L and R, the tangent and the cotangent product. The tangent product, also known as tensor product, if smooth is always Dirac, and we will describe how its characteristic foliation relates to those of L and R. The more novel cotangent product need not be Dirac even if smooth. When it is, we say that L and R concur. Concurrence captures commuting Poison structures and refines the Dirac pairs of Dorfman and Kosmann–Schwarzbach, and it is our proposal as the natural notion of “compatibility” between Dirac structures. We shall illustrate the usefulness of tangent- and cotangent products in general, and the notion of concurrence in particular.