Construction of String Solutions around Non-trivial Backgrounds

We present a way of constructing string solutions around non-trivial gravitational backgrounds. The proposed solutions are constructed using $N = 4$ superconformal building blocks with $\hat c = 4$. We give two different and inequivalent realizations of non-trivial four-dimensional subspaces, and we show the emergence of the $N = 4$ globally defined superconformal symmetry. The existence of $N = 4$ world-sheet symmetry stabilizes our solutions and implies in target space a number of covariantized supersymmetries around space-time dependent gravitational and dilaton backgrounds.Comment: Latex file, 15pp, CERN-TH.6790/9

Universal Thermal Instabilities and the High-Temperature Phase of the N=4 Superstrings

Using the properties of gauged N=4 supergravity, we show that it is possible to derive a universal thermal effective potential that describes all possible high-temperature instabilities of the known N=4 superstrings. These instabilities are due to non-perturbative dyonic modes, which become tachyonic in a region of the thermal moduli space M={s,t,u}; M is common to all non-perturbative dual-equivalent N=4 superstrings in five dimensions. We analyse the non-perturbative thermal potential and show the existence of a phase transition at high temperatures corresponding to a condensation of 5-branes. This phase is described in detail, using an effective non-critical string theory.Comment: 15 pages, LATEX file, no figure

Top quark mass: Latest CDF results, Tevatron combination and electroweak implications

A summary of the most up-to-date top quark mass measurements at CDF is presented. These analyses use top-antitop candidate events detected in the CDF experiment at the Tevatron collider with an integrated luminosity of up to ~3/fb. The combination of all those measurements together with the corresponding top mass measurements from the concurrently running D0 experiment at the Tevatron yields a world average of M_t=[173.1+/-0.6(stat.)+/-1.1(syst.)] GeV/c^2.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Teaching the expression of time:A concise framework

ELT materials adopt a system of twelve 'tenses'. Typically, they present three factors as affecting choice of 'tense': event time, event duration and speech time. This is misleading, as many more elements are in play. Their treatment is form-based, giving piecemeal information about the uses of the forms, or providing rules with quite a few exceptions or 'special cases', a practice that tends to confuse learners. This framework is informed by descriptive and theoretical accounts of English. It takes into consideration all the component elements of expressing time in English, including the meaning of verbs and speaker subjectivity. It presents a small number of consistent and flexible guidelines, provides a systematic visual representation of time reference and helps learners put in perspective the information in pedagogical materials

A humanities of resistance: fragments for a legal history of humanity

Law and the Humanities: An Introduction brings together a distinguished group of scholars from law schools and an array of the disciplines in the humanities. Contributors come from the United States and abroad in recognition of the global reach of this field. This book is, at one and the same time, a stock taking both of different national traditions and of the various modes and subjects of law and humanities scholarship. It is also an effort to chart future directions for the field. By reviewing and analyzing existing scholarship and providing thematic content and distinctive arguments, it offers to its readers both a resource and a provocation. Thus, Law and the Humanities marks the maturation of this ‘law and’ enterprise and will spur its further development