ar X iv : m at h / 03 05 34 2 v 1 [ m at h . O A ] 2 6 M ay 2 00 3 State spaces of JB ∗ - triples ∗ Matthew

ar X iv : m at h / 06 05 37 3 v 1 [ m at h . A G ] 1 5 M ay 2 00 6 FLATNESS OF THE LINKED GRASSMANNIAN

We show that the linked Grassmannian scheme, which arises in a functorial compactification of spaces of limit linear series, and in local models of certain Shimura varieties, is Cohen-Macaulay, reduced, and flat. We give an application to spaces of limit linear series.

ar X iv : m at h / 03 05 06 7 v 1 [ m at h . O C ] 4 M ay 2 00 3 Global Asymptotic Controllability Implies Input to State Stabilization ∗

We study nonlinear systems with observation errors. The main problem addressed in this paper is the design of feedbacks for globally asymptotically controllable (GAC) control affine systems that render the closed loop systems input to state stable with respect to actuator errors. Extensions for fully nonlinear GAC systems with actuator errors are also discussed.

ar X iv : m at h / 06 05 35 5 v 1 [ m at h . G R ] 1 3 M ay 2 00 6 Axes in Outer Space

ar X iv : h ep - p h / 03 05 16 5 v 1 1 5 M ay 2 00 3 The rise and fall of F 2 at low x

A short personal account is given of the impact of HERA data and the influence of Jan Kwiecinski on low x physics.

ar X iv : h ep - t h / 03 05 14 3 v 1 1 6 M ay 2 00 3 Krein structure of supersymmetry

We present supersymmetric positive definite scalar products together with natural Krein structures of supersymmetries.