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771	Vers une vérification expérimentale de la théorie de la relativité restreinte : réplication des expériences de Charles-Eugène Guye (1907-1921) / Towards an experimental verification of the special theory of relativity : replication of Charles-Eugène Guye’s experiments (1907-1921) Karim, Yacin 12 May 2011 (has links) Nous nous intéressons dans cette thèse à un aspect assez peu documenté de l'histoire de la théorie de la relativité restreinte, la recherche d'une vérification expérimentale de ses prédictions sur la variation de l'inertie en fonction de leur vitesse. Nous complétons les études historiques antérieures sur les expériences de Kaufmann (1906) et de Bucherer (1908), et montrons que la vérification de la formule de Lorentz-Einstein constitue encore un enjeu expérimental après 1911. Nous étudions plus particulièrement les recherches dirigées par Charles-Eugène Guye en collaboration avec ses étudiants Simon Ratnowsky (1907-1910) et Charles Lavanchy (1913-1915). Nous montrons que la seconde phase de ce travail est très largement considérée dans les années 1920 comme la vérifiation expérimentale la plus précise de la formule de Lorentz-Einstein. Nous utilisons la méthode de réplication, appliquée à l'expérience de Guye et Lavanchy. La très grande maîtrise de l'émission cathodique, associée à une méthode d'investigation spécifique, leur permet de surmonter toutes les difficultés identifiées alors comme préjudiciables au succès de ce type d'expérience. / We focus on an aspect of the history of special relativity theory that has not received much attention yet, namely the search for an experimental verification of the relativistic velocity dependency of inertia. Former historical studies on Kaufmann's 1906 and Bucherer's 1908 experiments are pursued. It is shown that verifying Lorentz-Einstein's formula is still a challenge after 1911. We concentrate here on Charles-Eugène Guye's works with students Simon Ratnowsky (1907-1910) and Charles Lavanchy (1913-1915). The second experiment is shown to be considered as the most precise verification of Lorentz-Einstein's formula by a large number of 1920s physicists. The replication method is used to probe Guye and Lavanchy's experiment. They are able to solve every then known difficulty in successfully performing such an experiment, through a great mastership of the crucial issue of cathode ray emission, together with a specific investigation method. Expérience de Guye et Lavanchy Théories de l'électron Théorie de la relativité restreinte Formule de Lorentz-Einstein Formule d'Abraham Charles-Eugène Guye Méthode de réplication Rayons cathodiques Guye and Lavanchy's experiment Electron theories Special relativity theory Lorentz-Einstein's formula Abraham's formula Charles-Eugène Guye Replication method Cathode rays 509
772	Negative frequency at the horizon : scattering of light at a refractive index front Jacquet, Maxime J. January 2017 (has links) This thesis considers the problem of calculating and observing the mixing of modes of positive and negative frequency in inhomogeneous, dispersive media. Scattering of vacuum modes of the electromagnetic field at a moving interface in the refractive index of a dielectric medium is discussed. Kinematics arguments are used to demonstrate that this interface may, in a regime of linear dispersion, act as the analogue of the event horizon of a black hole to modes of the field. Furthermore, a study of the dispersion of the dielectric shows that five distinct configurations of modes of the inhomogeneous medium at the interface exist as a function of frequency. Thus it is shown that the interface is simultaneously a black- and white-hole horizon-like and horizonless emitter. The role, and importance, of negative-frequency modes of the field in mode conversion at the horizon is established and yields a calculation of the spontaneous photonic flux at the interface. An algorithm to calculate the scattering of vacuum modes at the interface is introduced. Spectra of the photonic flux in the moving and laboratory frame, for all modes and all realisable increase in the refractive index at the interface are computed. As a result of the various mode configurations, the spectra are highly structured in intervals with black-hole, white-hole and no horizon. The spectra are dominated by a negative-frequency mode, which is the partner in any Hawking-type emission. An experiment in which an incoming positive-frequency wave is populated with photons is assembled to observe the transfer of energy to outgoing waves of positive and negative frequency at the horizon. The effect of mode conversion at the interface is clearly shown to be a feature of horizon physics. This is a classical version of the quantum experiment that aims at validating the mechanism of Hawking radiation. 530.14
773	Champs de Maxwell en espace-temps de Reissner - Nordstr∫m- De Sitter : décroissance et scattering conforme / Maxwell field on the Reissner-Nordst∫rm-De Sitter manifold : decay and conformal scattering Mokdad, Mokdad 30 September 2016 (has links) Nous étudions les champs de Maxwell à l'extérieur de trous noirs de Reissner-Nordstrom-de Sitter. Nous commençons par étudier la géométrie de ces espaces-temps : nous donnons une condition sous laquelle la métrique admet trois horizons puis dans ce cadre nous construisons l'extension analytique maximale d'un trou noir de Reissner-Nordstrom-de Sitter. Nous donnons ensuite une description générale des champs de Maxwell en espace-temps courbe, de leur décomposition en composantes spinorielle ainsi que de leur énergie. La première étude analytique établit la décroissance ponctuelle de champs de Maxwell à l'extérieur d'un trou noir de Reissner-Nordstrom-de Sitter ainsi que la décroissance uniforme de l'énergie sur un hyperboloïde qui s'éloigne dans le futur. Ce chapitre utilise des méthodes de champs de vecteurs (estimations d'énergie géométriques) dans l'esprit des travaux de Pieter Blue. Enfin nous construisons une théorie du scattering conforme pour les champs de Maxwell à l'extérieur du trou noir. Ceci consiste en la résolution du problème de Goursat pour les champs de Maxwell à la frontière isotrope de l'extérieur du trou noir, constituée des horizons du trou noir et horizons cosmologiques futurs et passés. Les estimations de décroissance uniforme de l'énergie sont cruciales dans cette partie. / We study Maxwell fields on the exterior of Reissner-Nordstrom-de Sitter black holes. We start by studying the geometry of these spacetimes: we give the condition under which the metric admits three horizons and in this case we construct the maximal analytic extension of the Reissner-Nordstrom-de Sitter black hole. We then give a general description of Maxwell fields on curves spacetimes, their decomposition into spin components, and their energies. The first result establishes the pointwise decay of the Maxwell field in the exterior of a Reissner-Nordstrom-de Sitter black hole, as well as the uniform decay of the energy flux across a hyperboloid that recedes in the future. This chapter uses the vector fields methods (geometric energy estimates) in the spirit of the work of Pieter Blue. Finally, we construct a conformal scattering theory for Maxwell fields in the exterior of the black hole. This amounts to solving the Goursat problem for Maxwell fields on the null boundary of the exterior region, consisting of the future and past black hole and cosmological horizons. The uniform decay estimates of the energy are crucial to the construction of the conformal scattering theory. Mathématiques Géométrie Physique mathématique Relativité générale Géométrie différentielle Géométrie Conforme Géométrie Lorentzienne Analyse EDP Décroissance des champs Trou Noir Théorie de Scattering Conforme Mathematics Geometry Mathematical Physics General Relativity Differential Geometry Conformal Geometry Lorentzian Geometry Analysis PDE Decay of fields Black Holes Conformal Scattering Theory 510
774	Coalescence de trous noirs en relativité générale & Le problème de la matière noire en astrophysique Le Tiec, Alexandre 27 September 2010 (has links) (PDF) La première partie de cette thèse s'inscrit dans le cadre de la modélisation des ondes gravitationnelles en provenance des systèmes binaires coalescents de trous noirs, dans la perspective de leur détection par les antennes gravitationnelles terrestres LIGO/VIRGO et spatiale LISA. Nous étudions la dynamique relativiste de tels systèmes binaires d'objets compacts à l'aide de deux méthodes d'approximation en relativité générale : les développements post-newtoniens, et le formalisme de la force propre, une extension naturelle de la théorie des perturbations d'un trou noir ; nous démontrons la cohérence des résultats ainsi obtenus dans leur domaine de validité commun. Dans un second temps, nous combinons ces deux méthodes perturbatives afin d'estimer l'effet de recul gravitationnel lors de la coalescence de deux trous noirs de Schwarzschild ; nos résultats sont en très bon accord avec ceux obtenus par des simulations en relativité numérique. La seconde partie de cette thèse traite du problème de la matière noire en astrophysique. L'hypothèse de la matière noire rend compte de nombreuses observations indépendantes de l'échelle des amas de galaxies jusqu'aux échelles cosmologiques. Les observations à l'échelle galactique sont toutefois en bien meilleur accord avec la phénoménologie de la dynamique newtonienne modifiée (MOND), qui postule une modification des lois de la gravité en l'absence de matière noire. Nous proposons une troisième alternative : conserver la théorie de la gravitation standard, mais doter la matière noire d'une propriété de polarisabilité dans un champ gravitationnel, de façon à rendre compte de la phénoménologie de MOND à l'échelle des galaxies. [PHYS:MPHY] Physics/Mathematical Physics relativité générale ondes gravitationnelles trous noirs post-newtonien cosmologie matière noire
775	Backward time travel and its relevance for theological study : An explorative literature study based on physics, philosophy, counterfactual thinking and theology Madfors, Ingela January 2011 (has links) This paper explores the possibility and relevance of theological study of backward time travel and its consequences. An examination of current research on backward time travel reveals a number of interdisciplinary topics which are not handled within physics. Some of these topics, mainly concerning free will and determination, are of interest to philosophers, whereas topics such as meaning and responsibility are left aside. In theology, there is a general dismissal of the idea of backward time travel. This study claims that this negative stance may be the result of taking science and its methods too seriously. The result of the study is that the interdisciplinary questions connected to backward time travel makes the subject very relevant for theological reflection. Thought experiments on backward time travel can provide valuable insights on how we deal with our lives, our world, time, and God today. / Denna explorativa studie utforskar möjligheten och relevansen av teologiska studier av tidsresor till det förflutna och deras konsekvenser. En undersökning av det aktuella forskningsläget visar på förekomsten av interdisciplinära frågeställningar som inte hanteras inom fysiken. Vissa frågor, framförallt knutna till den fria viljan och determinism, intresserar filosofer, medan andra områden som mening och ansvar inte behandlas vidare. Teologer ställer sig generellt negativa till tanken på resor till det förflutna. Denna studie hävdar att denna negativa inställning kan vara resultatet av en alltför stark respekt för vetenskapens fynd och metoder. Resultatet av studien är att de interdisciplinära frågeställningar som är kopplade till tidsresor till det förflutna gör ämnet högst lämpligt för teologisk begrundan. Tankeexperiment kring ämnet kan ge värdefulla insikter om hur vi hanterar våra liv, vår värld, tiden och Gud idag. backward time travel science-and-religion physics theology relativity theory logical paradoxes thought experiment counterfactual thinking post hoc prayer meaning co-creation responsibility memory relation process theology God tidsresor vetenskap-och-religion fysik teologi relativitetsteori logiska paradoxer tankeexperiment kontrafaktiskt tänkande post hoc bön mening medskapande ansvar minne relation processteologi Gud HUMANITIES and RELIGION HUMANIORA och RELIGIONSVETENSKAP Religion/Theology Religionsvetenskap/Teologi
776	Les contrats collectifs en droit québécois Silva, Ana Catarina 06 1900 (has links) No description available. Acte bilatéral Acte collectif Acte unilatéral Code de soumission Contrat Convention Déclaration de copropriété Effet relatif des contrats Assurance collective Tiers Agreement Bilateral act Collective act Contract Declaration of co-ownership Group insurance Relativity of contract Tendering code Third party Unilateral act
777	Ritual functions of the Book of Relevation: hope in dark times Van Rensburg, Hanré Janse 06 1900 (has links) Through a critical-functional, rather than literal, reading of the text of Revelation, this dissertation hypothesises a move beyond the paralysing constant reduction of hermeneutic meaning to two conventional poles when discussing hope – the early Christian movement’s hope through reversal, and contemporary nihilism. In order to do so in a responsible manner, it is necessary to study other research done on the topics of eschatology and hope – especially as seen in the book of Revelation. For this reason, the most popular and representative scholars of the Book of Revelation are studied. This overall look at current scholarships' views regarding the Apocalypse will help detect any possible missing elements in our approach to Revelation. But no study of this topic can be considered near complete if other disciplines are not involved; in this case especially when moving on to a critical-functional reading of Revelation. This thesis thus features an exploratory study of the functioning of ritual and hope within the human psyche; from archaeological to psychological perspectives. This emphasises the importance of, and leads into, the possibilities of a functional reading of the Book of Revelation. All of the above work leads to a re-evaluation of the success of hope as metanarrative for today. The suggestion is that Christian hope is not imaginary, but is irreducibly imaginative. For “reality is never just the world as it exists; it is the world as it is experienced through the lenses of social perception” (Barr 2010:636). / New Testament / D. Th. (New Testament and Early Christian Studies) Book of Revelation Apocalypse of John Critical-functional reading Cultural archaeology Progress Nihilism Eschatology Science and theology Representative studies Myth Ritual Liturgy Epistemology Theory of relativity Continuity and discontinuity Hope Optimism Metanarratives Psychological perspective Anthropology of experience Creating experience and meaning Resurrection Ritual possibilities 228.06 Bible. Revelation. -- Commentaries Hope in the Bible Symbolism in the Bible John, the Baptist, Saint -- Teachings Nihilism -- Religious aspects Eschatology -- Biblical teaching Religion and science -- Christianity
778	Des équations de contrainte en gravité modifiée : des théories de Lovelock à un nouveau problème de σk-Yamabe / On the constraint equations in modified gravity Lachaume, Xavier 15 December 2017 (has links) Cette thèse est consacrée au problème d’évolution des théories de gravité modifiée : après avoir rappelé ce qu’il en est pour la Relativité Générale (RG), nous exposons le formalisme n + 1 des théories ƒ(R), Brans-Dicke et tenseur-scalaire et redémontrons un résultat connu : le problème de Cauchy est bien posé pour ces théories, et les équations de contrainte se réduisent à celles de la RG avec un champ de matière. Puis nous effectuons la même décomposition n + 1 pour les théories de Lovelock et, ce qui est nouveau, ƒ(Lovelock). Nous étudions ensuite les équations de contrainte des théories de Lovelock et montrons qu’elles sont, dans le cas conformément plat et symétrique en temps, la prescription d’une somme de σk-courbures. Afin de résoudre cette équation de prescription, nous introduisons une nouvelle famille de polynômes semi-symétriques homogènes et développons des résultats de concavité pour ces polynômes. Nous énonçons une conjecture qui, si elle était avérée, nous permettrait de résoudre l’équation de prescription dans de nombreux cas : ∀ P;Q ∈ ℝ[X], avec deg P = deg Q = p, P et Q sont scindés => p ∑ k=0 P(k) Q(p-k) est scindé / This thesis is devoted to the evolution problem for modified gravity theories. After having explained this problem for General Relativity (GR), we present the n + 1 formalism for ƒ(R) theories, Brans-Dicke and scalar-tensor theories. We recall a known result: the Cauchy problem for these theories is well-posed, and the constraint equations are reduced to those of GR with a matter field. Then we proceed to the same n+1 decomposition for Lovelock and ƒ(Lovelock) theories, the latter being an original result. We show that in the locally conformally flat timesymmetric case, they can be written as the prescription of a sum of σk-curvatures. In order to solve the prescription equation, we introduce a new family of homogeneous semisymmetric polynomials and prove some concavity results for those polynomials. We express the following conjecture: if this is true, we are able to solve the prescription equation in many cases. ∀ P;Q ∈ ℝ[X], avec deg P = deg Q = p, P and Q are real-rooted => p ∑ k=0 P(k) Q(p-k) is real-rooted: Relativité Générale Équations de contrainte Problème de Cauchy "ƒ(R)" Tenseur-scalaire Lovelock "ƒ(Lovelock)" "σk-Yamabe" Polynômes symétriques élémentaires Concavité General Relativity Constraint equations Cauchy problem "ƒ(R)" Scalar-tensor Lovelock "ƒ(Lovelock)" "σk-Yamabe" Elementary symmetric polynomials Concavity
779	Bibelauslegung im Spannungsfeld von Methodenvielfalt und Eindeutigkeitsbestreben - Dargestellt, Untersucht und Gewertet unter Zuhilfenahme der Wirkungsgeschichte von Lukas 10,25-37 = Bible interpretation between methodological pluralityand the clarity of the text - described, examined and assessed with reference to the history of interpretation of Luke 10:25-37 / Bible interpretation between methodological plurality and the clarity of the text - described, examined and assessed with reference to the history of nthe interpretation of Luke 10:25-37 Klotz, Monika 30 November 2007 (has links) Text in German / Taking the plurality of methods in Biblical studies as starting point this dissertation shows a way to coherent interpretation message. An analysis of the current state and its long history identifies characteristics preventing clear interpretation results as well as ways to work out coherent interpretation messages. It is accompanied by five interpretations of Luke 10:25-37. An interdisciplinary excursus examines the legal interpretation with its claim of clarity. Three levels of interpretation are considered as essential for an adequate process of interpretation: 1. Clarification of the literal meaning on the basis of a historical exegesis. The author calls for the interdisciplinary cooperation of the methods and introduces a synthesis of methods. 2. Consideration of the reception history of texts. Special attention is given to the authority of interpretation in the Roman Catholic Church. The author regards "interpretive communities" as an alternative option. 3. The Holy Spirit's influence on the process of interpretation. Also in post-modern times interpreters need to "inhabit" the biblical texts. / Biblical and Ancient studies / M.Th. (New Testament) Hermeneutics History of biblical interpretation History of reception of the Bible Luke 10:25-37 "Good Samaritan" Relativity of meaning Synthesis of methods in biblical studies Interpretive communities 226.40601 Bible. N.T. -- Hermeneutics
780	Language use in industry Ribbens, Irene Rita 09 1900 (has links) An immense degree of linguistic diversity exists in the work force where it is possible for speakers of twenty-three home languages to come into contact on the work floor. The language of management in industry is predominantly English; while supervisors are primarily English- or Afrikaans-speaking. Misinterpretation of speaker intent plays a significant role in communication breakdown that occurs when management or foremen/supervisors communicate directly with workers who do not understand the two erstwhile official languages sufficiently or not at all. Reagan ( 1 986) hypothesized that the greatest number of problems are caused by what might be termed mutual ignorance, rather than by language difficulties. The aim of the thesis was therefore to establish what constitutes the mutual ignorance that leads to misinterpretation of speaker intent. The Hymesian model, the ethnography of speaking, was used as a model for an analysis of sociolinguistic features in factories in the Pretoria-WitwatersrandVereeniging area. For data collection a process of triangulation was used and qualitative and quantitative methods used. The Free Attitude Interview technique was used for unstructured interviews. Other methods include observation, and elicitation procedures such as the Discourse Completion Test, which were used in structured interviews. Language preference, forms of address and politeness markers were examined. Findings revealed that the major differences were found to be in the area of non-verbal behaviour. Speakers of Afrikaans and English are, on the whole, unaware of politeness markers used by speakers of African languages. Afrikaans and English speakers are unaware of offensive non-verbal behaviour used by them. It is revealing that speakers of the official languages believe this to be the very area that makes communication possible, but it is the area in which they may cause offence. It was also found that speakers of African languages have adopted many of the features of the power dominant group at work. The findings of the research are important for the development of strategies for overcoming misinterpretation of speaker intent and negative stereotyping. This research was undertaken as part of the Human Sciences Research Council's programme entitled Language in the labour situation. / Linguistics and Modern Languages / D.Litt. et Phil. (Linguistics) Language in industry Intercultural communication Miscommunication Sociolinguistics Discourse analysis Pragmatics Sociolinguistic relativity Communicative competence Forms of address Politeness markers 302.350968 Sociolinguistics Communicative competence Organizational behaviour -- South Africa Speech acts (Linguistics) Communication -- Social aspects Language and culture -- South Africa Symbolic interactionism

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