FONCTIONS DE CORRELATION EN THEORIE QUANTIQUE DES CHAMPS ET EN PHYSIQUE DE LA MATIERE CONDENSEE PDF Download

Author: HUBERT.. MABILAT
Publisher:
ISBN:
Category :
Languages : fr
Pages : 134

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DEUX FORMALISMES PRINCIPAUX SONT UTILISES POUR CALCULER DANS DIVERSES SITUATIONS LES FONCTIONS DE CORRELATION DE LA THEORIE QUANTIQUE DES CHAMPS : LE FORMALISME OPERATORIEL ET LE FORMALISME DE L'INTEGRALE DE CHEMIN. DANS LA PREMIERE PARTIE, LES DEUX FORMALISMES SONT UTILISES PARALLELEMENT DANS LE CADRE DE LA THEORIE DES CHAMPS A L'EQUILIBRE THERMIQUE, APPLIQUEE A LA PHYSIQUE DES PARTICULES, AFIN DE METTRE EN EVIDENCE L'ORIGINE DU CONTOUR D'INTEGRATION, DANS LE PLAN COMPLEXE EN TEMPS, QUI INTERVIENT DANS LE CALCUL DES FONCTIONS DE CORRELATION. LES DEUX ARTICLES PRESENTES PROPOSENT ENSUITE UNE DEMONSTRATION COMPLETE DU FORMALISME EN TEMPS REEL UTILISE COURAMMENT, FORMALISME QUI N'AVAIT JAMAIS ETE JUSTIFIE DE FACON RIGOUREUSE DANS LA LITTERATURE. DANS LA DEUXIEME PARTIE, ET TOUJOURS DANS LE CADRE DE LA PHYSIQUE DES PARTICULES, LE FORMALISME OPERATORIEL SEUL EST UTILISE POUR ABORDER LA NOTION DE HORS-EQUILIBRE, QUI JOUE UN ROLE IMPORTANT DANS LA PHYSIQUE DU PLASMA QUARK-GLUON. ON EVALUE EN PARTICULIER LA CONTRIBUTION DES SINGULARITES DE PINCEMENT. QUANT A LA TROISIEME PARTIE, ELLE S'INSCRIT DANS LE CADRE DE LA PHYSIQUE DE LA MATIERE CONDENSEE, ET L'INTEGRALE DE CHEMIN EST DE NOUVEAU UTILISEE POUR ETUDIER LE MODELE BOSONIQUE DE HUBBARD, QUI A DE NOMBREUSES APPLICATIONS EN SUPERFLUIDITE ET EN SUPRACONDUCTIVITE. LA THESE DECRIT UNE NOUVELLE DISCRETISATION DE L'INTEGRALE DE CHEMIN DANS L'OPTIQUE DE SIMULATIONS NUMERIQUES.

Author: FRANCOIS.. GELIS
Publisher:
ISBN:
Category :
Languages : fr
Pages : 454

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LE CADRE GENERAL DE CETTE THESE EST LA THEORIE DES CHAMPS A TEMPERATURE FINIE, ET PLUS PARTICULIEREMENT LE CALCUL PERTURBATIF DES FONCTIONS DE GREEN THERMIQUES. DANS UNE PREMIERE PARTIE SONT CONSIDERES TROIS PROBLEMES PLUTOT EN RELATION AVEC LE FORMALISME LUI MEME. APRES DEUX CHAPITRES INTRODUCTIFS DESTINES A METTRE EN PLACE LE CADRE ET LES NOTATIONS UTILISEES PAR LA SUITE, UN CHAPITRE EST DEDIE A CLARIFIER CERTAINS ASPECTS DE LA JUSTIFICATION DES REGLES DE FEYNMAN DU FORMALISME A TEMPS REEL. ENSUITE, JE M'INTERESSE DANS LE CHAPITRE 4 AU PROBLEME DES REGLES DE COUPURE DANS LES FORMALISMES A TEMPS REEL. EN PARTICULIER, OUTRE LA RESOLUTION D'UNE CONTROVERSE A CE SUJET, JE DONNE LES REGLES DE COUPURE A UTILISER DANS LA VERSION RETARDEE-AVANCEE DE CE FORMALISME. ENFIN, LE DERNIER PROBLEME ABORDE DANS LA PREMIERE PARTIE EST CELUI DE LA DESINTEGRATION DU PION EN DEUX PHOTONS DANS UN ENVIRONNEMENT THERMIQUE. J'Y MONTRE QUE LES CONTRADICTIONS EXISTANT DANS LA LITTERATURE A CE SUJET SONT DUES A CERTAINES PROPRIETES ANALYTIQUES DES FONCTIONS DE GREEN THERMIQUES. LA DEUXIEME PARTIE CONCERNE LE CALCUL DU TAUX DE PRODUCTION DE PHOTONS OU DE PAIRES DE LEPTONS (PHOTONS VIRTUELS) PAR UN PLASMA DE QUARKS ET DE GLUONS. LE CADRE DE CE TRAVAIL EST LA REORGANISATION DU DEVELOPPEMENT PERTURBATIF OBTENUE PAR LA SOMMATION DES DIAGRAMMES CONNUS SOUS LE NOM DE BOUCLES DURES. LE PREMIER VOLET DE CETTE ETUDE CONCERNE LA PRODUCTION DE PHOTONS VIRTUELS OU L'ON MONTRE QUE DES CONTRIBUTIONS IMPORTANTES ARRIVENT A DEUX BOUCLES ET COMPLETENT LE RESULTAT DEJA CONNU A UNE BOUCLE. L'AUTRE VOLET EST LA PRODUCTION DE PHOTONS REELS, POUR LESQUELS ON MONTRE QUE DES DIVERGENCES COLINEAIRES EXTREMEMENT FORTES RENDENT LES CONTRIBUTIONS A DEUX BOUCLES LARGEMENT DOMINANTES DEVANT LES CONTRIBUTIONS A UNE BOUCLE. DANS LES DEUX CAS, LE PHENOMENE OBSERVE PEUT ETRE INTERPRETE COMME DES INSUFFISANCES L'APPROXIMATION QUI CONDUIT AUX BOUCLES DURES.

Author: Cécile Dewitt-Morette
Publisher: Springer Science & Business Media
ISBN: 1489903194
Category : Science
Languages : en
Pages : 436

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The program of the Institute covered several aspects of functional integration -from a robust mathematical foundation to many applications, heuristic and rigorous, in mathematics, physics, and chemistry. It included analytic and numerical computational techniques. One of the goals was to encourage cross-fertilization between these various aspects and disciplines. The first week was focused on quantum and classical systems with a finite number of degrees of freedom; the second week on field theories. During the first week the basic course, given by P. Cartier, was a presentation of a recent rigorous approach to functional integration which does not resort to discretization, nor to analytic continuation. It provides a definition of functional integrals simpler and more powerful than the original ones. Could this approach accommodate the works presented by the other lecturers? Although much remains to be done before answering "Yes," there seems to be no major obstacle along the road. The other courses taught during the first week presented: a) a solid introduction to functional numerical techniques (A. Sokal) and their applications to functional integrals encountered in chemistry (N. Makri). b) integrals based on Poisson processes and their applications to wave propagation (S. K. Foong), in particular a wave-restorer or wave-designer algorithm yielding the initial wave profile when one can only observe its distortion through a dissipative medium. c) the formulation of a quantum equivalence principle (H. Kleinert) which. given the flat space theory, yields a well-defined quantum theory in spaces with curvature and torsion.

Author: V. Babelon
Publisher: Springer Science & Business Media
ISBN: 1461203155
Category : Mathematics
Languages : en
Pages : 368

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This book constitutes the proceedings of the International Conference on Integrable Systems in memory of J.-L. Verdier. It was held on July 1-5, 1991 at the Centre International de Recherches Mathematiques (C.I.R.M.) at Luminy, near Marseille (France). This collection of articles, covering many aspects of the theory of integrable Hamiltonian systems, both finite and infinite-dimensional, with an emphasis on the algebro-geometric meth ods, is published here as a tribute to Verdier who had planned this confer ence before his death in 1989 and whose active involvement with this topic brought integrable systems to the fore as a subject for active research in France. The death of Verdier and his wife on August 25, 1989, in a car accident near their country house, was a shock to all of us who were acquainted with them, and was very deeply felt in the mathematics community. We knew of no better way to honor Verdier's memory than to proceed with both the School on Integrable Systems at the C.I.M.P.A. (Centre International de Mathematiques Pures et Appliquees in Nice), and the Conference on the same theme that was to follow it, as he himself had planned them.

Author: Lars Hörmander
Publisher: Springer Science & Business Media
ISBN: 1461207754
Category : Mathematics
Languages : en
Pages : 384

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On March 17-19 and May 19-21,1995, analysis seminars were organized jointly at the universities of Copenhagen and Lund, under the heading "Danish-Swedish Analysis Seminar". The main topic was partial differen tial equations and related problems of mathematical physics. The lectures given are presented in this volume, some as short abstracts and some as quite complete expositions or survey papers. They span over a large vari ety of topics. The most frequently occurring theme is the use of microlocal analysis which is now important also in the study of non-linear differential equations although it originated entirely within the linear theory. Perhaps it is less surprising that microlocal analysis has proved to be useful in the study of mathematical problems of classical quantum mechanics, for it re ceived a substantial input of ideas from that field. The scientific committee for the invitation of speakers consisted of Gerd Grubb in Copenhagen, Lars Hormander and Anders MeHn in Lund, and Jo hannes Sjostrand in Paris. Lars Hormander and Anders Melin have edited the proceedings. They were hosts of the seminar days in Lund while Gerd Grubb was the host in Copenhagen. Financial support was obtained from the mathematics departments in Copenhagen and Lund, CNRS in France, the Danish and Swedish Na tional Research Councils, Gustaf Sigurd Magnuson's foundation at the Royal Swedish Academy of Sciences, and the Wenner-Gren foundation in Stockholm. We want to thank all these organisations for their support

Author:
Publisher:
ISBN:
Category : Chaotic behavior in systems
Languages : en
Pages : 130

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Author: Jacques Lafontaine
Publisher: Springer
ISBN: 3319207350
Category : Mathematics
Languages : en
Pages : 408

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This book is an introduction to differential manifolds. It gives solid preliminaries for more advanced topics: Riemannian manifolds, differential topology, Lie theory. It presupposes little background: the reader is only expected to master basic differential calculus, and a little point-set topology. The book covers the main topics of differential geometry: manifolds, tangent space, vector fields, differential forms, Lie groups, and a few more sophisticated topics such as de Rham cohomology, degree theory and the Gauss-Bonnet theorem for surfaces. Its ambition is to give solid foundations. In particular, the introduction of “abstract” notions such as manifolds or differential forms is motivated via questions and examples from mathematics or theoretical physics. More than 150 exercises, some of them easy and classical, some others more sophisticated, will help the beginner as well as the more expert reader. Solutions are provided for most of them. The book should be of interest to various readers: undergraduate and graduate students for a first contact to differential manifolds, mathematicians from other fields and physicists who wish to acquire some feeling about this beautiful theory. The original French text Introduction aux variétés différentielles has been a best-seller in its category in France for many years. Jacques Lafontaine was successively assistant Professor at Paris Diderot University and Professor at the University of Montpellier, where he is presently emeritus. His main research interests are Riemannian and pseudo-Riemannian geometry, including some aspects of mathematical relativity. Besides his personal research articles, he was involved in several textbooks and research monographs.

Author: P. M. Banks
Publisher: Elsevier
ISBN: 1483260666
Category : Science
Languages : en
Pages : 445

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Aeronomy, Part A is an attempt to make a comprehensive exposition of the processes in aeronomy, the study of composition, movement, and thermal balance of the upper regions of the planetary atmosphere. The text covers topics such as atmospheric regions and atmospheric density, the temperature and molecular mass of the atmosphere; the permanent constituents and the molecular and isotonic composition of the homosphere; and the transition from the homosphere to the heterosphere. Also covered are topics such as the temperature gradient and energies in the thermosphere, conditions at 200km and above 250km, solar radiation and ionization, and aeronomic reactions. The book is recommended for scientists, especially natural physicists, who would like to know more about the field of aeronomy and its advances.

Author: C.P. Enz
Publisher: Springer Science & Business Media
ISBN: 9401022747
Category : Language Arts & Disciplines
Languages : en
Pages : 568

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This collection of essays is intended as a tribute to Josef Maria Jauch on his sixtieth birthd~. Through his scientific work Jauch has justly earned an honored name in the community of theo retical physicists. Through his teaching and a long line of dis tinguished collaborators he has put an imprint on modern mathema tical physics. A number of Jauch's scientific collaborators, friends and admirers have contributed to this collection, and these essays reflect to some extent Jauch's own wide interests in the vast do main of theoretical physics. Josef Maria Jauch was born on 20 September 1914, the son of Josef Alois and Emma (nee Conti) Jauch, in Lucerne, Switzerland. Love of science was aroused in him early in his youth. At the age of twelve he came upon a popular book on astronomy, and an exam ple treated in this book mystified him. It was stated that if a planet travels around a centre of Newtonian attraction with a pe riod T, and if that planet were stopped and left to fall into the centre from any point of the circular orbit, it would arrive at the centre in the time T/I32. Young Josef puzzled about this for several months until he made his first scientific discovery : that this result could be derived from Kepler's third law in a quite elementary way.

Author: Sue Blattes
Publisher: L'Editeur : EDP Sciences
ISBN: 9782868835888
Category : English language
Languages : fr
Pages : 264

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Cet ouvrage, devenu célèbre sous son sigle MCSE, a déjà été utilisé par plus de 50 000 étudiants, chercheurs, professionnels. L'objectif est de lire et écrire des textes en anglais scientifique avec facilité et pertinence. L'ouvrage est conçu pour que l'apprenant devienne un véritable utilisateur de l'anglais. La méthode originale repose sur l'analyse des fonctions et structures nécessaires : measurement, frequency, comparison, modification, link words, time, cause and consequence, hypothesis, modality, purpose and process, impersonal forms, compound nouns and adjectives. Dans chaque unit, des tests d'auto-évaluation permettent de se situer et de construire son parcours de formation, d'abord en définissant ses objectifs à l'aide des key points et du lexis, puis, de façon plus personnalisée, en puisant dans les examples in context, checkpoints (back to basics, word web), web search, FAQs... MCSE est l'outil de base d'une méthode qui comprend aussi d'autres outils dans la même collection (Listening Comprehension for Scientiflc English et Speaking Skills in Scientitic English). L'ouvrage est destiné à tout apprenant de niveau baccalauréat qui désire acquérir une réelle compétence dans l'écriture et la lecture de textes en anglais scientifique.