The displacement operator is related to the displaced parity operator through a two dimensional Fourier transform. Both operators are important operators in phase space and the trace of both with respect to the density operator gives the Wigner functions (displaced parity operator) and Weyl functions (displacement operator). The generalisation of the parity-displacement operator relationship considered here is called the bi-fractional displacement operator, O(α, β; θα, θβ). Additionally, the bi-fractional displacement operators lead to the novel concept of bi-fractional coherent states. The generalisation from Fourier transform to fractional Fourier transform can be applied to other phase space functions. The case of the Wigner-Weyl function is considered and a generalisation is given, which is called the bi-fractional Wigner functions, H(α, β; θα, θβ). Furthermore, the Q−function and P−function are also generalised to give the bi-fractional Q−functions and bi-fractional P−functions respectively. The generalisation is likewise applied to the Moyal star product and Berezin formalism for products of non-commutating operators. These are called the bi-fractional Moyal star product and bi-fractional Berezin formalism. Finally, analysis, applications and implications of these bi-fractional transforms to the Heisenberg uncertainty principle, photon statistics and future applications are discussed.

Né en 1935 à Estérençuby (Pyrénées Atlantiques), Eñaut Etxamendi est écrivain, poète et chanteur en langue basque. Dans son œuvre narrative, il décrit la société agraire du Pays Basque Nord – concrètement, la province de la Basse-Navarre – et son processus de désagrégation sociale et culturelle à partir des années 60. Quelle place accorder dans la littérature basque moderne à cette œuvre, qui sublime l'idylle détruite ? Quelle est sa place et son originalité au vu des productions des auteurs basques contemporains? Quelle part de l’œuvre d’Etxamendi se situe sous l’influence de la pensée nationaliste et quel peut bien être son degré de participation à la construction de mythes identitaires? Nous utilisons les concepts du formalisme russe pour décrire la structure, le matériau littéraire et le dynamisme de l'œuvre etxamendienne. Puis, nous interrogeons ces résultats par l'apport du post-formalisme et des propositions bakhtiniennes et tâchons de situer l'œuvre littéraire d'Eñaut Etxamendi dans son rapport à l'idylle détruite et au Cкaз. Finalement, nous faisons intervenir l'ethnocritique de la littérature et le post-colonialisme, afin d'inscrire l'œuvre littéraire d'Eñaut Etxamendi dans « la mémoire longue d’une communauté discursive » et dans le contexte particulier des années 1960-1990 qui alliait la vitalité politique à la vitalité culturelle. L’objectif de ce questionnement est d’approfondir dans la connaissance de l’œuvre d’un auteur mais aussi d’une région littéraire du Pays Basque encore trop peu étudiées. / Eñaut Etxamendi was born in Esterençuby (Pyrénées Atlantiques, France), in 1935. He is a writer, poet an singer in basque language. In his literary work, Eñaut Etxamendi describes the agrarian society who was disappearing by the 60's in the North Basque Country – concretely in the province of Basse-Navarre – and the process of social and cultural disbanding that occured then.Where can be placed Eñaut Etxamendi's literary writing – sprung up in geographical and linguistic periphery – and its sublimated « idyllic chronotope » in basque modern literature ? Which is his originality comparing to other contemporary basque writer's works ? What is Etxamendi's part of work under nationalist theories's influence and up to which point has his literature pertained to the discourse of identity ? Our search is an attempt to improve knowledge of a few known author and few known literary area of Basque Country.

La théorie des spins élevés est le domaine de la physique théorique au centre de cette thèse. Le contexte général de la naissance de cette théorie est présentée dans l’introduction. La première partie est axée sur les ingrédients (méthode de Noether, fonctions génératrices et formalisme ambiant) permettant la construction de vertex cubiques entre un champ scalaire de matière et un champ de jauge de spin élevé dans un espace-temps à courbure constante à partir des courants conservés en espace-temps plat. Dans un second temps, nous préparons les éléments pour un futur test de la correspondance holographique à l’ordre cubique voire quartique en la constante de couplage. Plus précisément, nous révisons en détail le calcul de certains propagateurs, ce qui nous mène à calculer les fonctions à trois points impliquant deux scalaires. La dernière partie, bien que concernant toujours l’holographie des spins élevés, traite de la physique non-relativiste. Les symétries et les courants d’un gaz parfait/unitaire de Fermi y sont étudiés. Le lien entre physiques relativiste et non-relativiste est obtenue grâce à la réduction dimensionnelle de Bargmann. / The higher spin theory is the field of theoretical physics at the center of this thesis. The general context of the birth of this theory is presenting in the introduction. The first part focuses on the ingredients (Noether method, generating functions and ambient formalism) for the construction of cubic vertices between a scalar matter field and a higher spin gauge field in a constant curvature space-time from conserved currents in flat space-time. In a second step, we prepare the around for a future test of the holographic correspondence in the cubic or quartic order in the coupling constant. More specifically, we review in detail the computation of some propagators, which leads us to calculate three-point functions involving two scalars. The last part, although always on the higher spin holography, deals with non-relativistic physics. Symmetries and currents of an ideal or unitary Fermi gas are studied. The link between relativistic and non-relativistic physics is obtained by Bargmann dimensional reduction.

This study gives the Zulu's views and ideas about celestial bodies and associated natural phenomena and how they illustrate features in both the oral and written literature. It sketches various focussing mainly on The concentration is conceptions about the whole universe celestial bodies and natural phenomena. on the sun, moon, stars, thunder and lightning in poetry and prose both modern and traditional. Emphasis is on the fact that Zulus do not perceive celestial bodies as mere bodies but assign certain beliefs and philosophies to them. In examining these different conceptions, Western as well as African literary theories have been used in this study. I~ ~r=rli~ional izibongo amakhosi are associated with the sun, the moon as well as the stars. Their warriors' attack is associated with the thunderstorm. These celestial bodies are also used as determinants of time in terms of day and night, seasons and different times for different daily chores. In modern poetry these bodies are mainly associated with God and in some instances they are referred to as God himself. In prose they are used as determinants of time and are also used figuratively to describe certain circumstances. The study gives an idea of how Zulus in general perceive these celestial bodies and natural phenomena. / African Languages / D.Litt. et Phil. (African Languages)

De nos jours, la combustion représente encore un 90% de la production totale d'énergie au monde. La plupart des brûleurs de type industriel utilisent comme carburant des hydrocarbures en forme liquide. Cependant, un grand nombre d'études ont été dédiés aux flammes gazeuses et l'impact du spray liquide est encore loin d'être totalement compris. Le but de cet étude est l'amélioration de la modélisation des deux phénomènes principaux qui ont lieu entre l'atomisation du spray et la combustion, i.e. la dispersion des gouttes par la turbulence gazeuse et le procès d'évaporation dans le contexte de la Simulation Aux Grandes Echelles (SGE) des configurations complexes. Premièrement, l'approche Euler-Euler mésoscopique (Février et al. (2005)), basée sur une moyenne d'ensemble conditionnée et implémentée dans AVBP est amélioré. Le modèle de fermeture (Simonin et al. (2001); Kaufmann (2004)) pour les moments de deuxième ordre qui apparait dans les équations de transport résolues échoue quand appliqué à des configurations cisaillées (Riber (2007)). Plusieurs modèles proposés récemment par Masi (2010) et qui ont été valides a priori dans une configuration de nappe chargée de particules sont validés a posteriori dans la même configuration. Un analyse quantitative sur plusieurs cas avec diffèrent nombres de Stokes, nombres de Reynolds de la phase gazeuse et résolutions du maillage ont permit de retenir un modèle non-linéaire nommé 2EASM3, qui utilise le tenseur de déformations de la phase dispersée comme échelle de temps caractéristique. La deuxième partie a pour but l'amélioration du modèle d'évaporation implémenté dans AVBP. Ce modèle suppose une conduction infinie dans la phase liquide et symétrie sphérique dans la phase gazeuse ainsi que des lois simplifiées pour les propriétés thermodynamiques et de transport. Un nouveau modèle prenant en compte la dépendance de la viscosité du mélange gazeux avec la composition locale, et des nombres de Prandtl et Schmidt fixés par les valeurs à l'équilibre obtenus par moyen d'une simulation prenant en compte des lois complèxes pour les propriétés thermodynamiques et de transport est proposé. Cette nouvelle méthode produit des résultats en bon accord avec les mesures expérimentales pour l'évaporation d'une goutte isolé en une atmosphère d'azote au calme sans pourtant augmenter le cout du calcul. Finalement, l'impacte des nouveaux modèles est analysé dans une SGE de la configuration semi-industrielle MERCATO (García-Rosa (2008)). Bien que les données expérimentales ne soient pas suffisantes pour confirmer les résultats, les distributions de gouttes et de carburant gazeux sont significativement affectés par les modèles, ce qui pourrait avoir un impact directe sur le procès d'allumage. / Combustion still represents about 90% of the energy production in the world. Most industrial burners are fuelled with liquid hydrocarbons. However, most studies have been dedicated to gaseous ßames and the impact of liquid spray is still misunderstood. The purpose of this study is to improve the modelisation of two main phenomena occurring between atomization and combustion, i.e. the droplet dispersion in the turbulent gaseous flow and the evaporation process, in the context of Large Eddy Simulation (LES) of complex configurations. First, the mesoscopic Euler-Euler approach (Février et al. (2005)) based on a conditioned ensemble averaging and implemented in AVBP is improved. The closure model (Simonin et al. (2001), Kaufmann (2004)) for the second-order moments appearing in the transport equations solved fails in mean-sheared configurations (Riber (2007)). Several new models proposed by Masi (2010) and a priori tested in a particle-laden slab are tested a posteriori in the same configuration. A quantitative analysis based on several calculations varying the Stokes number, the gaseous Reynolds number and the grid resolution allows to retain a non-linear model using the particle rate-of-strain tensor as timescale and called 2EASM3. The second part consists in improving the evaporation model implemented in AVBP which assumes infinite conduction in the liquid and spherical symmetry in the gas phase along with simplified thermodynamics and transport properties calculation. A new model is proposed, where the dependence of gaseous mixture viscosity on local composition is accounted for, and the Prandtl and Schmidt numbers are fixed by a reference equilibrium calculation using complex thermodynamics and transport properties. This method shows good agreement with experimental measurements in the configuration of an isolated droplet evaporating in quiescent N2 without further increasing the computational cost. Finally, the impact of the new models is analysed in the LES of the MERCATO semi-industrial configuration (García-Rosa (2008)). Although the experimental data are not sufficient to confirm the results, both the droplet distribution and the fuel mass fraction are significantly affected, which would eventually affect the ignition process.

Centro Latino-Americano de Física / Os processos estocásticos com ruído branco multiplicativo são objeto de atenção constante em uma grande área da pesquisa científica. A variedade de prescrições possíveis para definir matematicamente estes processos oferece um obstáculo ao desenvolvimento de ferramentas gerais para seu tratamento. Na presente tese, estudamos propriedades de equilíbrio de processos markovianos com ruído branco multiplicativo. Para conseguirmos isto, definimos uma transformação de reversão temporal de tais processos levando em conta que a distribuição estacionária de probabilidade depende da prescrição. Deduzimos um formalismo funcional visando obter o funcional gerador das funções de correlação e resposta de um processo estocástico multiplicativo representado por uma equação de Langevin. Ao representar o processo estocástico neste formalismo (de Grassmann) funcional eludimos a necessidade de fixar uma prescrição particular. Neste contexto, analisamos as propriedades de equilíbrio e estudamos as simetrias ocultas do processo. Mostramos que, usando uma definição apropriada da distribuição de equilíbrio e considerando a transformação de reversão temporal adequada, as propriedades usuais de equilíbrio são satisfeitas para qualquer prescrição. Finalmente, apresentamos uma dedução detalhada da formulação supersimétrica covariante de um processo markoviano com ruído branco multiplicativo e estudamos algumas das relações impostas pelas funções de correlação através das identidades de Ward-Takahashi. / Multiplicativewhite-noise stochastic processes continuously attract the attention of a wide area of scientific research. The variety of prescriptions available to define it difficults the development of general tools for its characterization. In this thesis, we study equilibrium properties of Markovian multiplicative white-noise processes. For this, we define the time reversal transformation for this kind of processes, taking into account that the asymptotic stationary probability distribution depends on the prescription. We deduce a functional formalism to derive a generating functional for correlation and response functions of a multiplicative stochastic process represented by a Langevin equation. Representing the stochastic process in this functional (Grassmann) formalism, we avoid the necessity of fixing a particular prescription. In this framework, we analyze equilibrium properties and study hidden symmetries of the process. We show that, using a careful definition of equilibrium distribution and taking into account the appropriate time reversal transformation, usual equilibrium properties are satisfied for any prescription. Finally, we present a detailed deduction of a covariant supersymmetric formulation of a multiplicativeMarkovian white-noise process and study some of the constraints it imposes on correlation functions using Ward-Takahashi identities.

No description available.

Le concept d'hétérogène est souvent employé pour définir une littérature contemporaine qui transgresse les catégories génériques traditionnelles, multiplie les références littéraires, pratique les changements de registre, les ruptures narratives ou formelles, qui mêle fiction et réalité. Chez Olivier Cadiot, ce trait de non-genre – polygénéricité et amphibologie narrative – est au service d'une écriture de l'expérience subjective. La fiction se coule dans une forme piège pluridimensionnelle modelée sur le flux de la conscience et la volatilité de la pensée. Le récit brasse les images, les impressions fugitives, les configurations imaginaires, composant avec une matière textuelle sensible, émotionnellement dense. Déployant son plan de multiplicité, l'écriture cadiotienne de l'hétérogène intègre les fragments d’énoncés, les concepts, les données factuelles, les perceptions, les phénomènes psychiques, la mémoire individuelle dans un système textuel et expérientiel ouvert. / Le concept d'hétérogène est souvent employé pour définir une littérature contemporaine qui transgresse les catégories génériques traditionnelles, multiplie les références littéraires, pratique les changements de registre, les ruptures narratives ou formelles, qui mêle fiction et réalité. Chez Olivier Cadiot, ce trait de non-genre – polygénéricité et amphibologie narrative – est au service d'une écriture de l'expérience subjective. La fiction se coule dans une forme piège pluridimensionnelle modelée sur le flux de la conscience et la volatilité de la pensée. Le récit brasse les images, les impressions fugitives, les configurations imaginaires, composant avec une matière textuelle sensible, émotionnellement dense. Déployant son plan de multiplicité, l'écriture cadiotienne de l'hétérogène intègre les fragments d’énoncés, les concepts, les données factuelles, les perceptions, les phénomènes psychiques, la mémoire individuelle dans un système textuel et expérientiel ouvert.

Made available in DSpace on 2014-12-17T15:14:47Z (GMT). No. of bitstreams: 1 DarlanAM.pdf: 1159480 bytes, checksum: d201bf0e3558be6b14b14c9a86a46f20 (MD5) Previous issue date: 2005-03-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In this work we have studied the problem of percolation in a multifractal geometric support, in its different versions, and we have analysed the conection between this problem and the standard percolation and also the connection with the critical phenomena formalism. The projection of the multifractal structure into the subjacent regular lattice allows to map the problem of random percolation in the multifractal lattice into the problem of correlated percolation in the regular lattice. Also we have investigated the critical behavior of the invasion percolation model in this type of environment. We have discussed get the finite size effects / Nesta disserta??o estudamos o problema da percola??o num suporte geom?trico multifractal, em suas diferentes vers?es, e analisamos a conex?o deste problema com a percola??o convencional e com o formalismo dos fen?menos cr?ticos. A proje??o da estrutura multifractal numa rede regular subjacente permite mapear o problema da percola??o aleat?ria no multifractal num problema de percola??o correlacionada numa rede regular. Tamb?m investigamos o comportamento cr?tico do modelo da percola??o por invas?o neste tipo de ambiente e discutimos a quest?o do efeito de tamanho finito

Centro Latino-Americano de Física / Os processos estocásticos com ruído branco multiplicativo são objeto de atenção constante em uma grande área da pesquisa científica. A variedade de prescrições possíveis para definir matematicamente estes processos oferece um obstáculo ao desenvolvimento de ferramentas gerais para seu tratamento. Na presente tese, estudamos propriedades de equilíbrio de processos markovianos com ruído branco multiplicativo. Para conseguirmos isto, definimos uma transformação de reversão temporal de tais processos levando em conta que a distribuição estacionária de probabilidade depende da prescrição. Deduzimos um formalismo funcional visando obter o funcional gerador das funções de correlação e resposta de um processo estocástico multiplicativo representado por uma equação de Langevin. Ao representar o processo estocástico neste formalismo (de Grassmann) funcional eludimos a necessidade de fixar uma prescrição particular. Neste contexto, analisamos as propriedades de equilíbrio e estudamos as simetrias ocultas do processo. Mostramos que, usando uma definição apropriada da distribuição de equilíbrio e considerando a transformação de reversão temporal adequada, as propriedades usuais de equilíbrio são satisfeitas para qualquer prescrição. Finalmente, apresentamos uma dedução detalhada da formulação supersimétrica covariante de um processo markoviano com ruído branco multiplicativo e estudamos algumas das relações impostas pelas funções de correlação através das identidades de Ward-Takahashi. / Multiplicativewhite-noise stochastic processes continuously attract the attention of a wide area of scientific research. The variety of prescriptions available to define it difficults the development of general tools for its characterization. In this thesis, we study equilibrium properties of Markovian multiplicative white-noise processes. For this, we define the time reversal transformation for this kind of processes, taking into account that the asymptotic stationary probability distribution depends on the prescription. We deduce a functional formalism to derive a generating functional for correlation and response functions of a multiplicative stochastic process represented by a Langevin equation. Representing the stochastic process in this functional (Grassmann) formalism, we avoid the necessity of fixing a particular prescription. In this framework, we analyze equilibrium properties and study hidden symmetries of the process. We show that, using a careful definition of equilibrium distribution and taking into account the appropriate time reversal transformation, usual equilibrium properties are satisfied for any prescription. Finally, we present a detailed deduction of a covariant supersymmetric formulation of a multiplicativeMarkovian white-noise process and study some of the constraints it imposes on correlation functions using Ward-Takahashi identities.