Nonabelian Multiplicative Integration On Surfaces

ISBN: 9789814663847 出版年：2015 页码：186 Yekutieli Amnon World Scientific Publishing Company

We construct a 2-dimensional twisted nonabelian multiplicative integral. This is done in the context of a Lie crossed module (an object composed of two Lie groups interacting), and a pointed manifold. The integrand is a connection-curvature pair, that consists of a Lie algebra valued 1-form and a Lie algebra valued 2-form, satisfying a certain differential equation. The geometric cycle of the integration is a kite in the pointed manifold. A kite is made up of a 2-dimensional simplex in the manifold, together with a path connecting this simplex to the base point of the manifold. The multiplicative integral is an element of the second Lie group in the crossed module. We prove several properties of the multiplicative integral. Among them is the 2-dimensional nonabelian Stokes Theorem, which is a generalization of Schlesinger's Theorem. Our main result is the 3-dimensional nonabelian Stokes Theorem. This is a totally new result. The methods we used are: the CBH Theorem for the nonabelian exponential map; piecewise smooth geometry of polyhedra; and some basic algebraic topol- ogy. The motivation for this work comes from twisted deformation quantization. In the paper (Ye2) we encountered a problem of gluing nonabelian gerbes, where the input was certain data in differential graded algebras. The 2-dimensional multiplicative integral gives rise, in that situation, to a nonabelian 2-cochain; and the 3-dimensional Stokes Theorem shows that this cochain is a twisted 2-cocycle.