This dissertation covers two different but related topics: the construction of consistent models in type IIB and heterotic string theories, and the higher derivative couplings for D-brane action, which will enable us to relate some models of type IIB to the heterotic side through duality chain. In the first part, we describe an alternative to the KKLT scenario, in which one can achieve de-Sitter space after fixing all moduli. We fix complex structure moduli and the axio-dilaton by deriving the stability conditions for the critical points of the no-scale scalar potential that governs the dynamics of the complex structure moduli and the axio-dilaton in compactifications of type IIB string theory on Calabi-Yau three-folds. In the second part, we show the existence of a class of flux backgrounds in heterotic string theory. The background metric we will consider is a T2 fibration over a K3 base times four-dimensional Minkowski space. Unbroken space-time supersymmetry determines all background fields except one scalar function which is related to the dilaton. The heterotic Bianchi identity gives the same differential equation for the dilaton, and we will discuss in detail the solvability of this equation for backgrounds preserving an N=2 supersymmetry. In the third part, we obtain the higher derivative D-brane action by using both linearized T-duality and string disc amplitude computation. We evaluate disc amplitude of one R-R field C^(p-3) and two NS-NS fields in the presence of a single Dp-brane in type II string theory. We obtain the action for the higher derivative brane interactions among one R-R field C^(p-3) and two NS-NS B-fields after carefully comparing the supergravity amplitudes with the corresponding string amplitude up to alpha^r2 order. We also show that these higher derivative brane couplings are invariant under both R-R and NS-NS B-field gauge transformations, and compatible with linear T-duality.

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Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-10T12:24:26Z No. of bitstreams: 1 simplicianocastardellidosreis.pdf: 376769 bytes, checksum: 8142289023decc823720bd287ab4a490 (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: Corrigir no resumo as palavras: será vista e será considerada Depois serávista a ação efetiva induzida pela anomalia como consequência do traço do tensor-momento energia não ser nulo a nível quântico. Por fim, seráconsiderada a proposta da solução inomogênea do tipo Kasner e perspectivas futuras para essa solução on 2018-01-23T11:44:29Z (GMT) / Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-23T13:10:13Z No. of bitstreams: 1 simplicianocastardellidosreis.pdf: 376769 bytes, checksum: 8142289023decc823720bd287ab4a490 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-01-23T13:17:04Z (GMT) No. of bitstreams: 1 simplicianocastardellidosreis.pdf: 376769 bytes, checksum: 8142289023decc823720bd287ab4a490 (MD5) / Made available in DSpace on 2018-01-23T13:17:04Z (GMT). No. of bitstreams: 1 simplicianocastardellidosreis.pdf: 376769 bytes, checksum: 8142289023decc823720bd287ab4a490 (MD5) Previous issue date: 2015-08-05 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesta dissertação serão vistos elementos de teoria de gravitação modificada pelos efeitos quânticos e uma proposta de métrica inomogênea do tipo Kasner. Primeiramente, irá se abordar a teoria semiclássica, consistindo esta na quantização dos campos de matéria, deixando o campo gravitacional como um campo externo clássico. Depois será vista a ação efetiva induzida pela anomalia como consequência do traço do tensor-momento energia não ser nulo a nível quântico. Por fim, será considerada a proposta da solução inomogênea do tipo Kasner e perspectivas futuras para essa solução. / In this work will be seen gravitation theory elements modified by quantum effects and a pro-posal for inhomogeneous metric type Kasner. First, it will address the semiclassical theory, con-sisting in this quantization of matter fields, leaving the gravitational field as a classical external field. Then will be seen the effective action induced by anomaly as a result of energy-momentum tensor trace not be null in the quantum level. Finally, the proposal of the inhomogeneous solution of the Kasner type and future prospects for this solution will be considered

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-04-11T18:45:14Z No. of bitstreams: 1 jefersondiasgoncalves.pdf: 877599 bytes, checksum: 55b47e460c6f0960d499ee03cfdfbd27 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-04-11T19:36:44Z (GMT) No. of bitstreams: 1 jefersondiasgoncalves.pdf: 877599 bytes, checksum: 55b47e460c6f0960d499ee03cfdfbd27 (MD5) / Made available in DSpace on 2018-04-11T19:36:44Z (GMT). No. of bitstreams: 1 jefersondiasgoncalves.pdf: 877599 bytes, checksum: 55b47e460c6f0960d499ee03cfdfbd27 (MD5) Previous issue date: 2018-02-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesta tese expomos primeiramente um breve histórico-motivacional para a construção de uma teoria de gravitação quântica, bem como, rápidas revisões orientadas sobre elementos de teorias quânticas de campos e sobre a técnica de Schwinger-Dewitt. De posse destas ferramentas, discutimos a dependência de calibre e da parametrização para uma teoria quântica de gravitação em um espaço-tempo de dimensão arbitrária D. Com este objetivo, calculamos explicitamente as correções quânticas a 1-loop, da ação efetiva da teoria, considerando a parametrização mais geral possível para a métrica quântica. Essa parametrização contém inicialmente sete parâmetros, sendo que alguns deles serão fixados através da condição de fixação de calibre, o que torna o nosso cálculo um pouco mais simples. Por fim, para esta teoria, confirmamos a validade de um teorema geral, o qual garante a independência das divergências on-shell, a 1-loop, com respeito às ambiguidades nas escolhas de calibre e de parametrização da métrica quântica. / In this thesis we first present a brief historical-motivational for a construction of a theory of quantum gravitation, as well as quick reviews oriented on elements of quantum field theory and Schwinger- Dewitt technique. In possession of these tools, the gauge and parametrization dependence is discussed in quantum gravity in an arbitrary dimension D. Explicit one-loop calculations are performed within the most general parametrization of quantum metric with seven arbitrary parameters. On the other hand, some of the gauge fixing parameters are fixed to make the calculations relatively simple. We confirm the general theorem stating that the on shell local terms in the one-loop effective action are independent of the gauge and parametrization ambiguity.

Wir behandeln einige Spezialfälle von Beziehungen zwischen Eich- und Gravitationstheorien. Wir setzen den Schwerpunkt auf Baumlevelstreuamplituden in Einstein-(Skalar-)-Chromo-Dynamik, welche Streuungen zwischen Gluonen, massiven fundamentalen Quarks (Skalaren) und Gravitonen beschreibt. Wir untersuchen den endlichen Anteil von reiner Gluonenstreuung mit zwei kollinearen Gluonen. Basierend auf einem Vorschlag von S. Stieberger und T. Taylor, stehen diese in Beziehung zu Steuamplituden in Einstein-Yang-Mills Theorie, in welchen die kollinearen Gluonen durch ein Graviton ersetzt werden. Wir führen einen Beweis dieser Beziehungen unter der Ausnutzung des Cachazo-He-Yuan Formalismus durch. Parallel dazu werden wir einen Einblick in mysteriöse Wechselwirkunen dieser Beziehungen mit Eichinvarianzverletzungen des kollinearen Gluon Grenzwertes von Yang-Mills Streuampliuden geben. Danach behandeln wir eine andere Art von linearen Beziehungen zwischen Streuamplituden in Yang-Mills Theorie und Einstein-Yang-Mills Theorie, welche ebenfalls von S. Stieberger und T. Taylor vorgeschlagen wurden und direkt einzelne Gluonen mit einzelnen Gravitonen verbinden. Wir beweisen die Universalität dieser Beziehungen, in Anwesenheit von fundamental geladenen und massiven Fermionen und Skalaren. Schliesslich formulieren wir eine neue Zweifachkopiebeziehung zwischen klassisch effektiven Wirkungen. Die effektive Wirkung eines Systems von farblich geladenen, massiven und klassischen Weltlinien, welche über Yang-Mills wechselwirken, wird mit einem System von dilatonisch geladenen, massiven und klassischen Weltlinien, welche über Dilatongravitation wechselwirken, in Verbindung gesetzt. Somit verbessern wir eine, aus dem Kontext von Lösungen zu störungstheoretischen Bewegungsgleichungen, sowohl für das Gluon als auch für das Graviton, derselben Systeme, bekannte Zweifachkopievorschrift, formuliert von W. Goldberger und A. Ridgway. / We analyze several cases of mysterious connections between gauge and gravity theories, known as double copy relations. We focus on tree level scattering amplitudes in Einstein-(scalar-)-chromo-dynamics, i.e. scattering scenarios between gluons, massive fundamental quarks (scalars) and gravitons. In these scenarios we study the sub leading contribution to the adjacent collinear gluon limits in pure Yang-Mills amplitudes. Recently, S. Stieberger and T. Taylor have proposed a linear combination of amplitudes with a pair of collinear gluons to an Einstein-Yang-Mills amplitude. We present a proof of such relations using a novel representation of bosonic tree level amplitudes based on a localized integral on the Riemann sphere, called the Cachazo-He-Yuan formalism. Moreover, we give insight into an intriguing interplay between those relations and surprising gauge invariance violations of the sub-leading collinear gluon limit of Yang-Mills amplitudes. Next, we will focus on yet another set of relations between Yang-Mills amplitudes and Einstein-Yang-Mills amplitudes that were also proposed by S. Stieberger and T. Taylor. They directly relate single gluons to single gravitons. We show universality of such relations, i.e. their validity in the presence of massive fundamental quarks and scalars. For that purpose, we will use a Feynman diagrammatic approach which results in a novel color-to-kinematics rule, mapping gluons to gravitons in these scattering scenarios. Finally, we establish a novel double copy connection between classical effective actions of two massive classical worldlines which are colored and interacting in Yang-Mills theory and dilaton charged and interacting through dilaton-gravity. Doing so, we extend and improve existing work relating the same system of worldlines through a double copy at the level of perturbative solutions to the involved equations of motion for the gluon and graviton fields, as has been proposed by W. Goldberger and A. Ridgway.

Made available in DSpace on 2017-07-10T18:20:40Z (GMT). No. of bitstreams: 1 Rodrigo Rodrigues Dias.pdf: 1272431 bytes, checksum: 66200a310b22e91949a9710df73137d3 (MD5) Previous issue date: 2012-02-27 / The research seeks to investigate the relationship between the effective action of the Management Councils, as spaces for democratic participation, and the issues of binding and priority through the Municipal Council for the Rights of the Child and Adolescent of the City of Toledo / PR, based on the administrations of 2007/2009 and 2009/2011. By effective action, we understand the one which includes the participation of civil society in the debates, proposals and preparation of decisions about public policies in the municipal area of child and adolescent and seeks the means to enforce the substance of the decision by the municipal government. On the one hand, the binding, by legal and constitutional commandment, determines the inclusion, in public budgets, of the deliberated public policies by the Councils. On the other hand, there is also the prediction of priority attendance of the infantojuvenil demands, which must be accomplished by the actions of the Council, and reflects in the imposing of the deliberations. However, the reality of the Councils has shown that the Government has not converted the decisions in municipal public policies, which, in the area of Children and Youth, must be priority. Based on the analysis of the records in the course of two terms, we corroborate the explanation, formulated as initial working hypothesis, backed the Council's own behavior: the more effective is the Council's action, the more the Government will comply with their deliberations, including them in the budget and turning them into public policy. / A pesquisa busca verificar a relação entre a ação efetiva dos Conselhos Gestores, como espaços de participação democrática, e as questões da vinculação e da prioridade por meio do Conselho Municipal dos Direitos das Crianças e dos Adolescentes, da Cidade de Toledo/PR, com base nas gestões 2007/2009 e 2009/2011. Por ação efetiva entendemos aquela que contempla a participação da sociedade civil nos debates, na proposição e na elaboração de decisões sobre políticas públicas municipais na área da criança e do adolescente e que busca os meios de fazer valer o teor do decidido junto ao Poder Público Municipal. De um lado, a vinculação, por mandamento constitucional e legal, determina a inclusão, nos orçamentos públicos, das políticas públicas deliberadas nos âmbitos dos Conselhos. Por outro lado, também há previsão de atendimento prioritário às demandas da população infantojuvenil, que deve ser realizado pelas ações do Conselho, o que reflete na impositividade das deliberações. Entretanto, a realidade dos Conselhos tem demonstrado que o Poder Público não tem convertido as deliberações em políticas públicas municipais, as quais, na seara da Infância e da Juventude, têm de ser prioritárias. Com base na análise das atas, no decorrer das duas gestões, corroboramos a explicação, formulada como hipótese inicial de trabalho, a este descompasso, lastreada no comportamento do próprio Conselho: quanto mais efetiva for a ação do Conselho, mais o Poder Público acatará suas deliberações, incluindo-as no orçamento e transformando-as em políticas públicas.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-05-15T19:23:47Z No. of bitstreams: 1 tiberiodepaulanetto.pdf: 1926871 bytes, checksum: 17bceffda5c85de37a0d50a14f4f3f04 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-05-22T14:37:09Z (GMT) No. of bitstreams: 1 tiberiodepaulanetto.pdf: 1926871 bytes, checksum: 17bceffda5c85de37a0d50a14f4f3f04 (MD5) / Made available in DSpace on 2018-05-22T14:37:09Z (GMT). No. of bitstreams: 1 tiberiodepaulanetto.pdf: 1926871 bytes, checksum: 17bceffda5c85de37a0d50a14f4f3f04 (MD5) Previous issue date: 2017-02-22 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesta tese, exploram-se diferentes aspectos e aplicações das teorias gravitacionais com correções quânticas. O texto é dividido em três partes principais. Na primeira parte, são consideradas as soluções linearizadas em diferentes teorias de gravitação com derivadas superiores. O potencial Newtoniano é calculado nos modelos locais, super-renormalizáveis no nível quântico, e mostra-se que a singularidade Newtoniana é cancelada devido a contribuição dos modos massivos extras. Logo depois, o colapso gravitacional de uma pequena massa é estudado na gravitação não-local livre de fantasmas, sendo o principal resultado a ausência da singularidade na solução do campo gravitacional e a possibilidade da não formação do miniburaco negro como resultado do colapso. Na segunda parte, algumas questões sobre a inflação induzida pela anomalia conforme são estudadas. É discutida a possibilidade da transição entre os períodos de inflação estável para instável. É mostrado que esta transição é automática se as correções quânticas nesse período forem desprezadas. Em seguida, considera-se o efeito de termos que violam as simetrias de CPT e Lorentz na inflação induzida pela anomalia conforme. É demonstrado que os novos termos responsáveis por violar essas simetrias não afetam a dinâmica do fator de escala da métrica. Por fim, na terceira parte as correções quânticas para o modelo dos Galileons e para as teorias dos campos massivos tensoriais antissimétricos são obtidas. É mostrado que o propagador da teoria dos Galileons recebe correções quânticas com derivadas superiores e que o teorema de não-renormalização do modelo dos Galileons permanece, de uma maneira generalizada, válido na região das baixas energias. Depois, por meio de cálculos explícitos das correções quânticas semiclássicas não-locais é confirmada a equivalência quântica entre os modelos dos campos tensoriais antissimétricos massivos com a teoria de Proca e com o modelo do campo escalar massivo mínimo. / In this thesis, different aspects and applications of gravitational theories with quan-tum corrections are explored. The text is divided into three main parts. In the first part, the linearized solutions in different gravity theories with higher derivatives are considered. The Newtonian potential is calculated in the local models, super-renormalizable at the quantum level, and it is shown that the Newtonian singularity is cancelled due to the contributions of the extra massive modes. Then the gravitational collapse of a small mass is studied in non-local ghost-free gravity, being the main result the absence of singularity in the gravitational field solution and the possibility of non-mini black hole formation as the collapse result. In the second part, some issues about anomaly-induced inflation are studied. It is discussed the possibility of the transition between stable to unstable periods of inflation. It is shown that this transition is automatic if the quantum corrections in this period are neglected. In the following, we consider the effect of CPT and Lorentz-violating terms in the conformal anomaly-induced inflation. It is shown the new terms responsible to violate these symmetries do not affect the dynamics of the metric scale factor. Finally, in the third part, the quantum corrections for the Galileon model and for the theory of the massive antisymmetric tensor fields are obtained. It is shown that the propaga-tor of Galilean theory receives quantum corrections with higher derivatives and that the non-renormalization theorem for Galileon models remains, in a generalized way, valid in the low-energy region. Then, by means of explicit calculations of non-local semiclassical quantum corrections, the quantum equivalence between the massive antisymmetric tensor field models with the Proca theory and minimal massive scalar field model is confirmed.