Quantum revivals and carpets in some exactly solvable systems

We consider the revival properties of quantum systems with an eigenspectrum E_{n} proportional to n^{2}, and compare them with the simplest member of this class - the infinite square well. In addition to having perfect revivals at integer multiples of the revival time t_{R}, these systems all enjoy perfect fractional revivals at quarterly intervals of t_{R}. A closer examination of the quantum evolution is performed for the Poeschel-Teller and Rosen-Morse potentials, and comparison is made with the infinite square well using quantum carpets.Comment: 5 pages, 5 figures (1 new), minor additions, to appear in J. Phys.

Precision Tests of Electroweak Physics

We review the current status of precision electroweak measurements and the constraints they impose on new physics. We perform a model independent analysis using the STU-formalism of Ref. 1, and then discuss how the Z-pole data from LEP and SLD can be used to constrain models that are not covered within that framework.Comment: 1 cover page + 8 pages, 8 postscript figures, LaTeX2e, ws-p9-75x6-50.cls, Talk presented at Hadron 13, Mumbai, India, January 14-20, 199

Alʔilbīrī’s Book of the rational conclusions. Introduction, Critical Edition of the Arabic Text and Materials for the History of the Ḫawāṣṣic Genre in Early Andalus

[eng] The Book of the rational conclusions, written perhaps somewhen in the 10th c. by a physician from Ilbīrah (Andalus), is a multi-section medical pandect. The author brings together, from a diversity of sources, materials dealing with matters related to drug-handling, natural philosophy, therapeutics, medical applications of the specific properties of things, a regimen, and a dispensatory. This dissertation includes three different parts. First the transmission of the text, its contents, and its possible context are discussed. Then a critical edition of the Arabic text is offered. Last, but certainly not least, the subject of the specific properties is approached from several points of view. The analysis of Section III of the original book leads to an exploration of the early Andalusī assimilation of this epistemic tradition and to the establishment of a well-defined textual family in which our text must be inscribed. On the other hand, the concept itself of ‘specific property’ is often misconstrued and it is usually made synonymous to magic and superstition. Upon closer inspection, however, the alleged irrationality of the knowledge of these properties appears to be largely the result of anachronistic interpretation. As a complement of this particular research and as an illustration of the genre, a sample from an ongoing integral commentary on this section of the book is presented.[cat] El Llibre de les conclusions racionals d’un desconegut metge d’Ilbīrah (l’Àndalus) va ser compilat probablement durant la segona meitat del s. X. Es tracta d’un rudimentari però notablement complet kunnaix (un gènere epistèmic que és definit sovint com a ‘enciclopèdia mèdica’) en què l’autor aplega materials manllevats (sovint de manera literal i no-explícita) de diversos gèneres. El llibre obre amb una secció sobre apoteconomia (una mena de manual d’apotecaris) però se centra després en les diferents branques de la medicina. A continuació d’uns prolegòmens filosòfics l’autor copia, amb mínima adaptació lingüística, un tractat sencer de terapèutica, després un altre sobre les aplicacions mèdiques de les propietats específiques de les coses, una sèrie de fragments relacionats amb la dietètica (un règim en termes tradicionals) i, finalment, una col·lecció de receptes mèdiques. Cadascuna d’aquestes seccions mostren evidents lligams d’intertextualitat que apunten cap a una intensa activitat sintetitzadora de diverses tradicions aliades a la medicina a l’Àndalus califal. El text és, de fet, un magnífic objecte sobre el qual aplicar la metodologia de la crítica textual i de fonts. L’edició crítica del text incorpora la dimensió cronològica dins l’aparat, que esdevé així un element contextualitzador. Quant l’estudi de les fonts, si tot al llarg de la primera part d’aquesta tesi és només secundari, aquesta disciplina pren un protagonisme gairebé absolut en la tercera part, especialment en el capítol dedicat a l’anàlisi individual de cada passatge recollit en la secció sobre les propietats específiques de les coses