# Weak topology and a differentiable operator for Lipschitz maps

(Imperial College)

Many fundamental topologies in functional analysis arise as weak topologies. We show that the Scott topology induces a topology for real-valued Lipschitz maps on Banach spaces which we call the L-topology: It is the weakest topology with respect to which the domain-theoretic L-derivative operator, as a second order functional which maps the space of Lipschitz functions into the function space of non-empty weak* compact and convex valued maps equipped with the Scott topology, is continuous. For finite dimensional Euclidean spaces, where the L-derivative and the Clarke gradient coincide, we provide a simple characterisation of the basic open subsets of the L-topology in terms of ties or primitive maps of functions. We use this to verify that the L-topology is strictly coarser than the well-known Lipschitz norm topology. We then develop a fundamental theorem of calculus of second order in finite dimensions showing that the continuous integral operator from the continuous Scott domain of non-empty convex and compact valued functions to the continuous Scott domain of ties is inverse to the continuous operator induced by the L-derivative.

**Tuesday 27th May 2008, 14:00**

Robert Recorde Room

Department of Computer Science