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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Teoria de calibre em dimensões dois e quatro / Gauge theory in dimensions two and four

De Martino, Marcelo Gonçalves, 1986- 12 February 2011 (has links)
Orientador: Marcos Benevenuto Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica / Made available in DSpace on 2018-08-19T09:52:31Z (GMT). No. of bitstreams: 1 DeMartino_MarceloGoncalves_M.pdf: 1604556 bytes, checksum: be41ad6ca9fd66921624adce95bf0939 (MD5) Previous issue date: 2012 / Resumo: Este trabalho procurou apresentar os conhecimentos básicos necessários para trabalhar com a teoria de calibre em baixas dimensões e também mostrar algumas aplicações da mesma. Na parte básica da teoria, além de comentar aspectos da teoria de Hodge para variedades compactas, também se discute, com certo nível de detalhes, os conceitos de fibrados vetoriais e conexões, com ênfase dada para os cálculos locais com conexões e curvaturas. Duas aplicações mais concretas da teoria de calibre são apresentadas nesta dissertação. Primeiro, em dimensão quatro, discute-se a equação de Yang-Mills sobre 4-variedades e é apresentada uma solução para a equação anti-auto-dual, solução esta que é conhecida na literatura como ansatz de 't Hooft. Por fim, é apresentada a prova, baseado no artigo [DONALDSON, 1983], de um importante teorema devido a M. S. Narasimhan e C. S. Seshadri que relaciona os conceitos de estabilidade com o de existência de conexão unitária satisfazendo certa propriedade, em fibrados vetoriais complexos sobre superfícies de Riemann / Abstract: In this work it is developed the basic knowledge required to deal with gauge theory in low dimension and it is shown some applications of this theory. Regarding the basic knowledge, apart from discussing some aspects of Hodge theory over compact manifolds, it is also covered, with a certain deal of details, the concepts of vector bundles and connections, paying close attention to the local computations regarding connections and curvature. As for the applications of the theory, we start, in dimension four, by treating the Yang-Mills equation over 4-manifolds and it is showed a solution to the anti-self-dual Yang-Mills equation, solution that is known in the literature as the 't Hooft ansatz. At last, it is given a proof, following the paper [DONALDSON, 1983], of an important theorem due to M. S. Narasimhan and C. S. Seshadri that relates the algebro-geometric notion of stability to the differential-geometric notion of existence of unitary connection whose curvature satisfies a certain condition, on vector bundles over Riemann surfaces / Mestrado / Matematica / Mestre em Matemática
102

Identification des mécanismes périphériques impliqués dans la douleur chronique expérimentale des muscles de la mastication

Ferreira, Renato Alves 12 1900 (has links)
L’objectif premier de notre projet était d’établir un modèle animal de douleur chronique orofaciale, lequel pourrait imiter la sensibilité retrouvée chez les patients souffrant de douleur orofaciale myalgique. Nous avons procédé à des injections intramusculaires de saline acide (2 injections à 2 jours d’intervalle pH 4.0) pour induire une sensibilisation mécanique des mucles massétérins. La réponse nocifensive a été mesurée à l’aide de filaments de von Frey avant et après ces injections dans des rats Sprague-Dawley. Par la suite, le potentiel analgésique de différents antagonistes des récepteurs glutamatergiques fût évalué par l’injection intramusculaire de ces antagonistes à différents moments. Nos résultats suggèrent que deux injections de saline acide, produisent une hypersensibilité mécanique signalée par l’augmentation du nombre de réponses à l’application de filaments de von Frey. Cet effet dure plusieurs semaines et est bilatéral, même lorsque les injections sont unilatérales, indiquant qu’une composante centrale est forcément impliquée. Toutefois, une composante périphérique impliquant les récepteurs glutamatergiques semble présider le tout puisque les antagonistes glutamatergiques, appliqués de façon préventive empêchent le développement de l’hypersensibilité. Cependant, le maintien de cette hypersensibilité doit dépendre de mécanismes centraux puisque l’application d’antagonistes une fois la sensibilisation induite, ne diminue en rien le nombre de réponses obtenues. Ce modèle semble approprié pour reproduire une hypersensibilité musculaire durable de bas niveau. Nos données indiquent que les récepteurs glutamatergiques périphériques participent à l’induction de cette hypersensibilité de longue durée. Nous croyons que ce modèle pourra éventuellement contribuer à une meilleure compréhension des mécanismes à l’origine des myalgies faciales persistantes. / The first objective of this project was to establish an animal model of chronic orofacial pain, which could mimic symptoms of patients suffering from orofacial myalgia. We used acidic saline injections (2 injections, 2 days apart at pH 4.0) in masseteric muscles to induce mechanical hypersensitivity. Nocifensive behavior was measured before and after the injections using von Frey filaments in male Sprague Dawley rats. Later, the potential analgesic effect of glutamate receptors antagonists was measured by intramuscular administration of these antagonists at different times. Our results suggest that two injections of acidic saline produce a mechanical hypersensitivity as reflected by the increased number of responses to applications of von Frey filaments. This effect lasts several weeks and is bilateral, even when the injections are unilateral, indicating that a central component must be involved. However, the initial stage of induction of this hypersensitivity involves peripheral glutamate receptors since injection of their antagonists before the second acidic saline injection prevents development of the nocifensive response, whereas their injection at later times is ineffective in blocking development of the response. This model based on a double injection of acidic saline seems appropriate to reproduce low intensity, long-lasting muscle pain. Our data suggests that peripheral glutamate receptors are involved in the induction of this long-term hypersensitivity. We believe that this model may contribute to a better understanding of the mechanisms behind persistent orofacial muscle pain.
103

Laços de Wilson supersimétricos na correspondência AdS/CFT / Supersymmetric Wilson loops in the AdS/CFT correspondence

Kuraoka, Dhyan Victor Hiromitsu 29 May 2013 (has links)
O objetivo desta dissertação é revisar os operadores laços de Wilson no contexto da correspondência AdS/CFT. Estes operadores, presentes em qualquer teoria de calibre, são importantes por nos fornecer um parâmetro de ordem para a transição de fase confinante/desconfinante. Além disso, eles são particularmente importantes no estudo da correspondência AdS/ CFT pois: i) Eles nos dão, em alguns casos, resultados exatos graças ao fato de poderem ser localizados em um modelo de matrizes, desta forma nos permitindo fazer testes altamente não triviais da correspondência; ii) Eles são os objetos da teoria de calibre que são duais as cordas propagando no interior do espaço, nos dando um rico dicionário entre quantidades no interior (AdS) e na borda do espaço (CFT). Depois de revisarmos os laços de Wilson em teorias de calibre e a correspondência Ads/CFT, introduziremos a definição dos laços de Wilson supersimétricos 1/2 BPS. Calcularemos eles para o caso de um acoplamento fraco e para qualquer outro valor da constante de acoplamento usando técnicas de modelos de matrizes. Finalmente, compararemos nossos resultados com computações de superfícies minimais no interior do espaço, encontrando uma concordância perfeita. / The aim of this thesis is to review Wilson loop operators in the contexto f the AdS/CFT correspondence. These operators, wich are present in any gauge theory, are important because they furnish an order parameter for confinement/deconfinement phase transitions. Besides this, they are particularly relevant in the study of the AdS/CFT correspondence because: i) they allow, in some cases, for exact results thanks to localization to matrix models and make it possible to perform highly non-trivial tests of the correspondence; ii) they are the gauge theory objects dual to strings propagating in the bulk of the space and give a rich dictionary between bulk (AdS) and boundary (CFT) quantities. After reviews of Wilson loops in gauge theories and of the Ads/CFT correspondence, we will introduce the definition of 1/2 BPS supersymmetric Wilson loops, we will compute them at weak coupling and then at any order in the coupling constant via matrix model techniques, and finally we will compare our results with minimal surface computations in the bulk, finding perfect agreement.
104

5,56 x 45 mm FMJ i Afghanistan : amerikanska och brittiska stridserfarenheter av kaliberns effekt

Modigh, Johan January 2010 (has links)
<p>Uppsatsens huvudsyfte är att undersöka om amerikanska och brittiska stridserfarenheter av kalibern 5,56 i Afghanistan kan bidra till att utveckla den svenska Försvarsmaktens taktiska förmåga. Anledningen till varför jag valde att utgå från dessa länder är därför att de har fler öppna källor samt har mer erfarenhet än många andra. Studien genomfördes genom en kvalitativ textanalys av bland annat reglementen, rapporter och artiklar. Uppsatsen visar att Försvarsmaktens kaliber till sin automatkarbin, 5,56, var potent för stridstaktikanpassad för invasionsförsvar. Detta delvis på grund av kaliberns egna logistiska fördelar men även därför att de prioriterade vapensystemen för infanteriförbanden, lätta pansarvärnsvapnen, innebar relativt korta stridsavstånd. Studien visar därefter att idag, för amerikanska och brittiska styrkor i dagens konflikt i Afghanistan, är 5,56 otillräcklig. Stridsavstånden är generellt för långa för att kalibern skall avge sin optimala verkan i målet. Studien belyser vad dessa nationer vidtagit för åtgärder, samt vilka åtgärder som planeras eller finns som förslag för att förbättra sin stridstaktiska förmåga. Den mest optimala förbättringen anser många är att byta ut kalibern 5,56 mot en grövre mellankaliber i spannet 5,56-7,62. Förslag som förändrad skjututbildning, optikutveckling och nya vapeninköp nämns också. I diskussionen diskuteras om eller hur den svenska Försvarsmakten kan dra nytta av de andra nationernas erfarenheter. Resonemanget ger det generella slutsatsen att Försvarsmakten kan utveckla sin stridstaktiska förmåga genom att studera andra nationer. Ett snabbt konkret exempel vore att implementera skarpskyttevapnet ak4 med förstorande optiskt hjälpmedel i svenska Försvarsmaktens skytteförband.</p> / <p>The main purpose with this study is to investigate whether U.S. and British combat experience of the caliber 5.56 in Afghanistan is helping to develop the Armed Forces' tactical ability. The reason why I chose to rely on these countries is because they have more unclassified sources and has more combat experience than many others. This study was conducted through a qualitative text analysis of for example regulations, reports and articles. This essay shows that the Swedish Armed Forces standard caliber that is being used in today’s assault rifle (ak5c), were potent in battle tactics designed for the defence of Sweden. This is partly becauseof 5,56 own logistical advantages and also because light anti-tank weapons had priority over small arms weapons. This resulted in relatively short shooting distances. The study shows thereafter that the U.S. and British troops in today's conflict in Afghanistan, thinks that 5.56 is insufficient. Combat distances are generally too long for the caliber to deliver its optimum effect in the target. The study highlights what kind of actions these nations have taken, and what measures are planned to improve its combat tactical ability. The study reveals that the most optimal improvement, are to replace the 5.56 with a bigger medium sized caliber. Proposals to change the marksmanship training, optics development and to purchase new weapons are also mentioned. In the end of this essay there is a discussion on, or how the Swedish Armed Forces can implement U.S and British experiences. The reasoning in the final chapter gives the general answer that the Swedish Armed Forces indeed can develop their tactical combat skills by studying other nations. An example would be to implement the older ak4 with magnifying optics that could improve the longer range capabilities of the infantry units.</p>
105

5,56 x 45 mm FMJ i Afghanistan : amerikanska och brittiska stridserfarenheter av kaliberns effekt

Modigh, Johan January 2010 (has links)
Uppsatsens huvudsyfte är att undersöka om amerikanska och brittiska stridserfarenheter av kalibern 5,56 i Afghanistan kan bidra till att utveckla den svenska Försvarsmaktens taktiska förmåga. Anledningen till varför jag valde att utgå från dessa länder är därför att de har fler öppna källor samt har mer erfarenhet än många andra. Studien genomfördes genom en kvalitativ textanalys av bland annat reglementen, rapporter och artiklar. Uppsatsen visar att Försvarsmaktens kaliber till sin automatkarbin, 5,56, var potent för stridstaktikanpassad för invasionsförsvar. Detta delvis på grund av kaliberns egna logistiska fördelar men även därför att de prioriterade vapensystemen för infanteriförbanden, lätta pansarvärnsvapnen, innebar relativt korta stridsavstånd. Studien visar därefter att idag, för amerikanska och brittiska styrkor i dagens konflikt i Afghanistan, är 5,56 otillräcklig. Stridsavstånden är generellt för långa för att kalibern skall avge sin optimala verkan i målet. Studien belyser vad dessa nationer vidtagit för åtgärder, samt vilka åtgärder som planeras eller finns som förslag för att förbättra sin stridstaktiska förmåga. Den mest optimala förbättringen anser många är att byta ut kalibern 5,56 mot en grövre mellankaliber i spannet 5,56-7,62. Förslag som förändrad skjututbildning, optikutveckling och nya vapeninköp nämns också. I diskussionen diskuteras om eller hur den svenska Försvarsmakten kan dra nytta av de andra nationernas erfarenheter. Resonemanget ger det generella slutsatsen att Försvarsmakten kan utveckla sin stridstaktiska förmåga genom att studera andra nationer. Ett snabbt konkret exempel vore att implementera skarpskyttevapnet ak4 med förstorande optiskt hjälpmedel i svenska Försvarsmaktens skytteförband. / The main purpose with this study is to investigate whether U.S. and British combat experience of the caliber 5.56 in Afghanistan is helping to develop the Armed Forces' tactical ability. The reason why I chose to rely on these countries is because they have more unclassified sources and has more combat experience than many others. This study was conducted through a qualitative text analysis of for example regulations, reports and articles. This essay shows that the Swedish Armed Forces standard caliber that is being used in today’s assault rifle (ak5c), were potent in battle tactics designed for the defence of Sweden. This is partly becauseof 5,56 own logistical advantages and also because light anti-tank weapons had priority over small arms weapons. This resulted in relatively short shooting distances. The study shows thereafter that the U.S. and British troops in today's conflict in Afghanistan, thinks that 5.56 is insufficient. Combat distances are generally too long for the caliber to deliver its optimum effect in the target. The study highlights what kind of actions these nations have taken, and what measures are planned to improve its combat tactical ability. The study reveals that the most optimal improvement, are to replace the 5.56 with a bigger medium sized caliber. Proposals to change the marksmanship training, optics development and to purchase new weapons are also mentioned. In the end of this essay there is a discussion on, or how the Swedish Armed Forces can implement U.S and British experiences. The reasoning in the final chapter gives the general answer that the Swedish Armed Forces indeed can develop their tactical combat skills by studying other nations. An example would be to implement the older ak4 with magnifying optics that could improve the longer range capabilities of the infantry units.
106

Identification des mécanismes périphériques impliqués dans la douleur chronique expérimentale des muscles de la mastication

Ferreira, Renato Alves 12 1900 (has links)
L’objectif premier de notre projet était d’établir un modèle animal de douleur chronique orofaciale, lequel pourrait imiter la sensibilité retrouvée chez les patients souffrant de douleur orofaciale myalgique. Nous avons procédé à des injections intramusculaires de saline acide (2 injections à 2 jours d’intervalle pH 4.0) pour induire une sensibilisation mécanique des mucles massétérins. La réponse nocifensive a été mesurée à l’aide de filaments de von Frey avant et après ces injections dans des rats Sprague-Dawley. Par la suite, le potentiel analgésique de différents antagonistes des récepteurs glutamatergiques fût évalué par l’injection intramusculaire de ces antagonistes à différents moments. Nos résultats suggèrent que deux injections de saline acide, produisent une hypersensibilité mécanique signalée par l’augmentation du nombre de réponses à l’application de filaments de von Frey. Cet effet dure plusieurs semaines et est bilatéral, même lorsque les injections sont unilatérales, indiquant qu’une composante centrale est forcément impliquée. Toutefois, une composante périphérique impliquant les récepteurs glutamatergiques semble présider le tout puisque les antagonistes glutamatergiques, appliqués de façon préventive empêchent le développement de l’hypersensibilité. Cependant, le maintien de cette hypersensibilité doit dépendre de mécanismes centraux puisque l’application d’antagonistes une fois la sensibilisation induite, ne diminue en rien le nombre de réponses obtenues. Ce modèle semble approprié pour reproduire une hypersensibilité musculaire durable de bas niveau. Nos données indiquent que les récepteurs glutamatergiques périphériques participent à l’induction de cette hypersensibilité de longue durée. Nous croyons que ce modèle pourra éventuellement contribuer à une meilleure compréhension des mécanismes à l’origine des myalgies faciales persistantes. / The first objective of this project was to establish an animal model of chronic orofacial pain, which could mimic symptoms of patients suffering from orofacial myalgia. We used acidic saline injections (2 injections, 2 days apart at pH 4.0) in masseteric muscles to induce mechanical hypersensitivity. Nocifensive behavior was measured before and after the injections using von Frey filaments in male Sprague Dawley rats. Later, the potential analgesic effect of glutamate receptors antagonists was measured by intramuscular administration of these antagonists at different times. Our results suggest that two injections of acidic saline produce a mechanical hypersensitivity as reflected by the increased number of responses to applications of von Frey filaments. This effect lasts several weeks and is bilateral, even when the injections are unilateral, indicating that a central component must be involved. However, the initial stage of induction of this hypersensitivity involves peripheral glutamate receptors since injection of their antagonists before the second acidic saline injection prevents development of the nocifensive response, whereas their injection at later times is ineffective in blocking development of the response. This model based on a double injection of acidic saline seems appropriate to reproduce low intensity, long-lasting muscle pain. Our data suggests that peripheral glutamate receptors are involved in the induction of this long-term hypersensitivity. We believe that this model may contribute to a better understanding of the mechanisms behind persistent orofacial muscle pain.
107

Simetrias chiral e de sabor em QCD holográfica : estados excitados do píon, acoplamentos fortes de mésons charmosos e catálise magnética inversa /

Pereira, Carlisson Miller Cantanhede January 2017 (has links)
Orientador: Gastão Inácio Krein / Resumo: Existem poucas dúvidas de que a QCD seja a teoria correta das interações fortes. As dificuldades em resolver a teoria em baixas energias no regime fortemente acoplado e não perturbativo tem deixado sem respostas muitas questões importantes, tais como a natureza do confinamento e o mecanismo de hadronização. Diversos métodos têm sido usados para estudar suas propriedades e consequências a baixas energias. Esses métodos incluem a QCD na rede, as equações de Dyson- Schwinger, a teoria de perturbação chiral e os modelos de quarks. Recentemente, a dualidade gauge/gravidade tem fornecido uma nova maneira de acessar o regime fortemente acoplado de uma teoria de calibre via uma teoria de gravidade dual, em especial da QCD através de modelos holográficos. Tais modelos são usualmente denominados modelos holográficos para a QCD, ou apenas modelos AdS/QCD. Nesta tese investigamos importantes problemas de interesse atual em física hadrônica envolvendo as quebras das simetrias chiral e de sabor usando modelos holográficos para a QCD. Estes problemas são: (1) o desaparecimento das constantes de decaimento leptônicas dos estados excitados do pion no limite quiral; (2) os efeitos da quebra de simetria de sabor no acoplamentos do méson rho aos mésons charmosos D and D^{*} e seus fatores de forma eletromagnéticos; (3) os efeitos de um campo magnético e da temperatura sobre o condensado quiral, sinalizando uma catálise magnética inversa. / Abstract: There is little doubt that QCD is the correct theory for the strong interactions. The difficulties in solving the theory at low energies in the strongly interacting, non-perturbative regime have left unanswered many important questions, such as the nature of confinement and the mechanism of hadronization. Several approaches have been used to study its properties and consequences at low energies. These include lattice QCD, Dyson-Schwinger equations, chiral perturbation theory and quark models. More recently, the gauge/gravity duality has provided a new way to access the strongly coupled regime of a gauge theory via a dual gravity theory, in special of QCD through holographic models. Such models are usually named as holographic QCD models, or just AdS/QCD models. In this thesis, we investigate three problems of contemporary interest in hadronic physics involving the chiral and flavor symmetries holographic QCD models. These problems are: (1) the vanishing of the leptonic decay constants of the excited states of the pion in the chiral limit; (2) the effects of the flavor symmetry breaking on the strong couplings of the rho meson to the charmed D and D^{*} mesons and the their electromagnetic form factors; (3) the effects of a magnetic field and temperature on the chiral condensate, signalizing inverse magnetic catalysis. / Doutor
108

Estudo do escalonamento de volume finito na transição de fase do grupo de calibre Z(2) na rede / Study of the finite volume escalation of the phase transition of Z(2) gauge group on the lattice

Arthur Rodrigues Jardim Barreto 13 July 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho estudamos a dependência com o tamanho do sistema dos observáveis relacionados com a transição de fase de 1 ordem do rupo de calibre Z(2) em 4 dimensões. Foram realizadas simulações de Monte Carlo numa rede cúbica para diferentes valores da aresta, utilizando o método do Banho Térmico para sortear os elementos do grupo na rede. / In this work we study the dependence of the observable related to the size of the system to the phase transition of first order of the Z(2) gauge group in 4 dimensions. Monte Carlo simulations were performed on a cubic lattice for different values of the edge, using the method of the Heat Bath to randomize the group members in the lattice.
109

Simetrias chiral e de sabor em QCD holográfica: estados excitados do píon, acoplamentos fortes de mésons charmosos e catálise magnética inversa / Chiral and flavor symmetries in holographic QCD: pion excited states, strong couplings of charmed mesons and inverse magnetic catalysis

Pereira, Carlisson Miller Cantanhede [UNESP] 16 August 2017 (has links)
Submitted by Carlisson Miller Cantanhede Pereira (miller@ift.unesp.br) on 2017-09-13T20:55:23Z No. of bitstreams: 1 Tese_Carlisson_Miller.pdf: 3316974 bytes, checksum: b3c4fb6f0c7fe685339da7e2dc50fc18 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-09-15T13:43:04Z (GMT) No. of bitstreams: 1 pereira_cmc_dr_ift.pdf: 3316974 bytes, checksum: b3c4fb6f0c7fe685339da7e2dc50fc18 (MD5) / Made available in DSpace on 2017-09-15T13:43:04Z (GMT). No. of bitstreams: 1 pereira_cmc_dr_ift.pdf: 3316974 bytes, checksum: b3c4fb6f0c7fe685339da7e2dc50fc18 (MD5) Previous issue date: 2017-08-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Existem poucas dúvidas de que a QCD seja a teoria correta das interações fortes. As dificuldades em resolver a teoria em baixas energias no regime fortemente acoplado e não perturbativo tem deixado sem respostas muitas questões importantes, tais como a natureza do confinamento e o mecanismo de hadronização. Diversos métodos têm sido usados para estudar suas propriedades e consequências a baixas energias. Esses métodos incluem a QCD na rede, as equações de Dyson- Schwinger, a teoria de perturbação chiral e os modelos de quarks. Recentemente, a dualidade gauge/gravidade tem fornecido uma nova maneira de acessar o regime fortemente acoplado de uma teoria de calibre via uma teoria de gravidade dual, em especial da QCD através de modelos holográficos. Tais modelos são usualmente denominados modelos holográficos para a QCD, ou apenas modelos AdS/QCD. Nesta tese investigamos importantes problemas de interesse atual em física hadrônica envolvendo as quebras das simetrias chiral e de sabor usando modelos holográficos para a QCD. Estes problemas são: (1) o desaparecimento das constantes de decaimento leptônicas dos estados excitados do pion no limite quiral; (2) os efeitos da quebra de simetria de sabor no acoplamentos do méson rho aos mésons charmosos D and D^{*} e seus fatores de forma eletromagnéticos; (3) os efeitos de um campo magnético e da temperatura sobre o condensado quiral, sinalizando uma catálise magnética inversa. / There is little doubt that QCD is the correct theory for the strong interactions. The difficulties in solving the theory at low energies in the strongly interacting, non-perturbative regime have left unanswered many important questions, such as the nature of confinement and the mechanism of hadronization. Several approaches have been used to study its properties and consequences at low energies. These include lattice QCD, Dyson-Schwinger equations, chiral perturbation theory and quark models. More recently, the gauge/gravity duality has provided a new way to access the strongly coupled regime of a gauge theory via a dual gravity theory, in special of QCD through holographic models. Such models are usually named as holographic QCD models, or just AdS/QCD models. In this thesis, we investigate three problems of contemporary interest in hadronic physics involving the chiral and flavor symmetries holographic QCD models. These problems are: (1) the vanishing of the leptonic decay constants of the excited states of the pion in the chiral limit; (2) the effects of the flavor symmetry breaking on the strong couplings of the rho meson to the charmed D and D^{*} mesons and the their electromagnetic form factors; (3) the effects of a magnetic field and temperature on the chiral condensate, signalizing inverse magnetic catalysis.
110

Estudo do escalonamento de volume finito na transição de fase do grupo de calibre Z(2) na rede / Study of the finite volume escalation of the phase transition of Z(2) gauge group on the lattice

Arthur Rodrigues Jardim Barreto 13 July 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho estudamos a dependência com o tamanho do sistema dos observáveis relacionados com a transição de fase de 1 ordem do rupo de calibre Z(2) em 4 dimensões. Foram realizadas simulações de Monte Carlo numa rede cúbica para diferentes valores da aresta, utilizando o método do Banho Térmico para sortear os elementos do grupo na rede. / In this work we study the dependence of the observable related to the size of the system to the phase transition of first order of the Z(2) gauge group in 4 dimensions. Monte Carlo simulations were performed on a cubic lattice for different values of the edge, using the method of the Heat Bath to randomize the group members in the lattice.

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