/ 02 01 12 4 v 1 1 6 Ja n 20 02 NIKHEF 01 - 018 Aspects of BRST Quantization †

/ 02 01 07 6 v 1 1 3 Ja n 20 02 INRNE - TH - 02 - 01 Positive Energy Unitary Irreducible Representations of D = 6 Conformal

We give a constructive classification of the positive energy (lowest weight) unitary irreducible representations of the D = 6 superconformal algebras osp(8 * /2N). Our results confirm all but one of the conjectures of Minwalla on this classification. Our main tool is the explicit construction of the norms of the states that has to be checked for positivity. We give also the reduction of the fou...

ua nt - p h / 02 01 12 9 v 1 2 8 Ja n 20 02 Vector coherent state representations , induced representations , and geometric quantization : I . Scalar coherent state representations

Coherent state theory is shown to reproduce three categories of representations of the spectrum generating algebra for an algebraic model: (i) classical realizations which are the starting point for geometric quantization; (ii) induced unitary representations corresponding to prequantization; and (iii) irreducible unitary representations obtained in geometric quantization by choice of a polariz...

/ 02 01 28 9 v 1 3 0 Ja n 20 02 The η ′ → ηππ decay in U ( 3 ) chiral perturbation theory 1

/ 01 01 02 2 v 1 1 7 Ja n 20 01 NEW RESULTS ON α S AND OPTIMIZED SCALES

A summary of the latest αs results at LEP1 and LEP2 from event-shape predictions at O(α 2 s)+NLLA is presented. Later these are compared to measurements obtained using the Experimentally Optimized Scale method. Finally the αs measurement from the 4-jet rate is discussed.

Preconditioning Legendre Spectral Collocation Approximations to Elliptic Problems

This work deals with the H1 condition numbers and the distribution of the ~ N;Msingular values of the preconditioned operators f~ 1 N;M WN;M ÂN;Mg. ÂN;M is the matrix representation of the Legendre Spectral Collocation discretization of the elliptic operator A de ned by Au := u + a1ux + a2uy + a0u in (the unit square) with boundary conditions: u = 0 on 0; @u @ A = u on 1. ~ N;M is the sti ness ...