In the recent control literature there has been a great interest in controller design techniques which are robust with respect to plant perturbations. Crucial for all robustness studies is of course the availability of a “good metric” defined on the set of all plants. A metric is considered good if it can be easily computed and if it gives a measure of numerical robustness. On the set of proper...

Abstract. We prove Strichartz estimates for the absolutely continuous evolution of a Schrödinger operator H = (i∇ + A) + V in R, n ≥ 3. Both the magnetic and electric potentials are time-independent and satisfy pointwise polynomial decay bounds. The vector potential A(x) is assumed to be continuous but need not possess any Sobolev regularity. This work is a refinement of previous methods, which...

The terminology and notation used here have been introduced in the following articles: [9], [4], [13], [12], [10], [8], [2], [3], [1], [14], [7], [11], [5], and [6]. Let M be a metric structure, and let x, y be elements of the carrier of M . The predicate x ≈ y is defined by: (Def.1) ρ(x, y) = 0. Let M be a metric structure, and let x be an element of the carrier of M . The functor x yielding a...