Fields and rings with few types

Let R be an associative ring with possible extra structure. R is said to be weakly small if there are countably many 1-types over any finite subset of R. It is locally P if the algebraic closure of any finite subset of R has property P. It is shown here that a field extension of finite degree of a weakly small field either is a finite field or has no Artin-Schreier extension. A weakly small field of characteristic 2 is finite or algebraically closed. Every weakly small division ring of positive characteristic is locally finite dimensional over its centre. The Jacobson radical of a weakly small ring is locally nilpotent. Every weakly small division ring is locally, modulo its Jacobson radical, isomorphic to a product of finitely many matrix rings over division rings

Supersymmetric CP-violating Currents and Electroweak Baryogenesis

In this work we compute the CP-violating currents of the right-handed stops and Higgsinos, induced by the presence of non-trivial vacuum expectation values of the Higgs fields within the context of the minimal supersymmetric extension of the Standard Model (MSSM) with explicit CP-violating phases. Using the Keldysh formalism, we perform the computation of the currents at finite temperature, in an expansion of derivatives of the Higgs fields. Contrary to previous works, we implement a resummation of the Higgs mass insertion effects to all orders in perturbation theory. While the components of the right-handed stop current j^\mu_{\widetilde t_R} become proportional to the difference H_2 \partial^{\mu}H_1-H_1 \partial^{\mu} H_2 (suppressed by \Delta\beta), the Higgsino currents, j^\mu_{\widetilde{H}_i}, present contributions proportional to both H_2 \partial^{\mu}H_1\pm H_1 \partial^{\mu} H_2. For large values of the charged Higgs mass and moderate values of \tan\beta the contribution to the source proportional to H_2 \partial^{\mu}H_1+H_1 \partial^{\mu} H_2 in the diffusion equations become sizeable, although it is suppressed by the Higgsino number violating interaction rate \Gamma_\mu^{-1/2}. For small values of the wall velocity, 0.04\simlt v_\omega \simlt 0.1, the total contribution leads to acceptable values of the baryon asymmetry for values of the CP-violating phases \phi_{CP} in the range 0.04\simlt|\sin\phi_{CP}|\simlt 1. Finally, we comment on the relevance of the latest results of Higgs searches at LEP2 for the mechanism of electroweak baryogenesis within the MSSM.Comment: 27 pages, 4 figures, latex2e. Typo corrected and references adde

Boston University Symphony Orchestra and Symphonic Chorus, November 22, 2004

This is the concert program of the Boston University Symphony Orchestra and Symphonic Chorus performance on Monday, November 22, 2004 at 8:00 p.m., at Symphony Hall, 301 Massachusetts Avenue. Works performed were "Nachtlied," Op. 108 by Robert Schumann, "Moirologhia" (world premiere) by Theodore Antoniou, 'Wotan's Farewell' and 'Magic Fire Music' from "Die Walküre" by Richard Wagner, and "Francesca da Rimini," Op. 39 by Pyotr Il'yich Tchaikovsky. Digitization for Boston University Concert Programs was supported by the Boston University Center for the Humanities Library Endowed Fund