Gauge techniques in time and frequency domain TLM

Typical features of the Transmission Line Matrix (TLM) algorithm in connection with stub loading techniques and prone to be hidden in common frequency domain formulations are elucidated within the propagator approach to TLM. In particular, the latter reflects properly the perturbative character of the TLM scheme and its relation to gauge field models. Internal 'gauge' degrees of freedom are made explicit in the frequency domain by introducing the complex nodal S-matrix as a function of operators that act on external or internal fields or virtually couple the two. As a main benefit, many techniques and results gained in the time domain thus generalize straight away. The recently developed deflection method for algorithm synthesis, which is extended in this paper, or the non-orthogonal node approximating Maxwell's equations, for instance, become so at once available in the frequency domain. In view of applications in computational plasma physics, the TLM model of a relativistic charged particle current coupled to the Maxwell field is treated as a prototype.Comment: 20 pages; Keywords: Gauge techniques, perturbative schemes, TLM method, propagator approach, plasma physic

Constrained fitting of three-point functions

We determine matrix elements for $B \to D$ semileptonic decay. The use of the constrained fitting method and multiple smearings for both two- and three-point correlators allows an improved calculation of the form factors.Comment: Talk given at Lattice2001(heavyquark), 3 pages, 4 figure

Civil Justice Systems in Europe and the United States

Professor Dr. Hein D. Kötz - dean of Bucerius Law School in Hamburg, Germany, and a leading scholar in comparative law - presents the inaugural Herbert L. Bernstein Memorial Lecture titled, Civil Justice Systems in Europe and the United States

Restriction of stable rank two vector bundles in arbitrary characteristic

Let $X$ be a smooth variety defined over an algebraically closed field of arbitrary characteristic and \O_X(H) be a very ample line bundle on $X$. We show that for a semistable $X$-bundle $E$ of rank two, there exists an integer $m$ depending only on $\Delta(E).H^{\dim(X)-2}$ and $H^{\dim(X)}$ such that the restriction of $E$ to a general divisor in $|mH|$ is again semistable. As corollaries we obtain boundedness results, and weak versions of Bogomolov's theorem and Kodaira's vanishing theorem for surfaces in arbitrary characteristic.Comment: LaTeX document, 16 pages, no figure