Studies on Wilson loops, correlators and localization in supersymmetric quantum field theories

In this thesis we study at perturbative level correlation functions of Wilson loops (and local operators) and their relations to localization, integrability and other quantities of interest as the cusp anomalous dimension and the Bremsstrahlung function. First of all we consider a general class of 1/8 BPS Wilson loops and chiral primaries in N=4 Super Yang-Mills theory. We perform explicit two-loop computations, for some particular but still rather general configuration, that confirm the elegant results expected from localization procedure. We find notably full consistency with the multi-matrix model averages, obtained from 2D Yang-Mills theory on the sphere, when interacting diagrams do not cancel and contribute non-trivially to the final answer. We also discuss the near BPS expansion of the generalized cusp anomalous dimension with L units of R-charge. Integrability provides an exact solution, obtained by solving a general TBA equation in the appropriate limit: we propose here an alternative method based on supersymmetric localization. The basic idea is to relate the computation to the vacuum expectation value of certain 1/8 BPS Wilson loops with local operator insertions along the contour. Also these observables localize on a two-dimensional gauge theory on S^2, opening the possibility of exact calculations. As a test of our proposal, we reproduce the leading Luscher correction at weak coupling to the generalized cusp anomalous dimension. This result is also checked against a genuine Feynman diagram approach in N=4 super Yang-Mills theory. Finally we study the cusp anomalous dimension in N=6 ABJ(M) theory, identifying a scaling limit in which the ladder diagrams dominate. The resummation is encoded into a Bethe-Salpeter equation that is mapped to a Schroedinger problem, exactly solvable due to the surprising supersymmetry of the effective Hamiltonian. In the ABJ case the solution implies the diagonalization of the U(N) and U(M) building blocks, suggesting the existence of two independent cusp anomalous dimensions and an unexpected exponentation structure for the related Wilson loops.

A revista Veja e a construção da realidade dos evangélicos no Brasil: uma análise do discurso.

A dissertação de mestrado A revista Veja e a construção da realidade dos evangélicos no Brasil: uma análise do discurso , não objetiva julgar como certo ou errado o procedimento das diferentes correntes religiosas do segmento cristão brasileiro ou mesmo do jornalismo que as reporta, mas sim, avaliar como um dos periódicos mais conceituados e lidos no país destaca fatos e temas referentes ao segmento cristão evangélico, em sua cobertura jornalística, participando do processo social de construção da realidade. Para compreender este processo, utilizou-se a técnica de Análise do Discurso, com base no método qualitativo, visando explorar, entender e descobrir a forma como a revista Veja reporta o segmento religioso. O corpus definido são as nove matérias de capa que destacam os evangélicos durante 42 anos de circulação do periódico (1968-2010) que totalizam 2197 edições da revista Veja. Para se estabelecer um comparativo quanto à abordagem sobre outros segmentos cristãos, um mesmo número de edições que destacaram o Catolicismo Romano, foram igualmente analisadas. A pesquisa é orientada pela hipótese de que o discurso contido nas reportagens constrói uma imagem negativa dos evangélicos por meio do recurso a um tom irônico e dá ênfase em situações que envolvem escândalos e questões financeiras. Esta hipótese também se assenta na compreensão de que jornalistas não são profissionais técnicos desprovidos de imaginação e visões de mundo, neste caso, de um imaginário em torno da religião, que faz parte da construção noticiosa da qual participam. As Teorias do Imaginário, juntamente com as Teorias do Discurso e as Teorias do Jornalismo (Produção da Notícia) servirão de base para a compreensão do fenômeno e para a análise do objeto, que será conduzida por meio do método da Análise do Discurso. Espera-se que esta pesquisa contribua na indicação de caminhos para facilitar o diálogo entre a sociedade, entidades religiosas e profissionais envolvidos na produção de mensagem midiáticas, contribuindo para uma cultura de paz e de respeito à diversidade religiosa e à pluralidade de idéias presentes na sociedade brasileira, enfatizando, neste sentido, os valores éticos do profissional de comunicação.

JORNALISTAS NO CINEMA: REPRESENTAÇÕES E APROPRIAÇÕES

No contexto da comunicação midiática e suas mediações socioculturais, a tese traz como proposta central uma análise das representações do jornalista no cinema e das apropriações dessas narrativas por aqueles que desejam seguir a profissão no futuro. Buscou-se mostrar que o cinema contribui no imaginário sobre a profissão, trazendo estereótipos sobre o fazer jornalístico. Além disso, ele influencia muitos a seguirem a carreira, também colaborando na forma como os estudantes acreditam que será sua profissão no futuro. O corpus da pesquisa é constituído por 50 filmes que apresentam jornalistas, sendo que três foram analisados em profundidade, por trazerem temas recorrentes e criarem traços de mitologia sobre a profissão: A montanha dos sete abutres, Todos os homens do presidente e Intrigas de Estado. Os parâmetros metodológicos incluem: o levantamento bibliográfico, a análise em profundidade, a exibição de obras, a realização de debates livres e a aplicação de questionários estruturados. A fundamentação teórica inclui autores como Edgar Morin, Stella Senra, Brian McNair, Roland Barthes, Cornelius Castoriadis, Raymond Williams e Jesús Martín-Barbero.Como objetivos específicos, buscou-se: 1) realizar um panorama dos Journalism movies e sua evolução, determinando tipos e temas recorrentes; 2) identificar a criação de possíveis mitologias sobre o Jornalismo por meio do cinema; 3) identificar sintonias e dissonâncias na forma como as imagens são apropriadas por estudantes de Jornalismo, contribuindo na criação de um imaginário próprio sobre a profissão.

JORNAL SUPER NOTÍCIA: SENSACIONALISMO OU POPULARIZAÇÃO DA NOTÍCIA?

Esta dissertação apresenta um estudo do jornal impresso, com foco no jornal diário, delimitado no tabloide Super Notícia , de Belo Horizonte (MG). A escolha de tal impresso se deu por ser ele um fenômeno editorial de vendas e de publicidade, dentro dos estilos reconhecidos como popular e popularesco, com páginas diárias contendo desde notícia policial até receita de bolo. Ao analisar um objeto jornalístico é necessário verificar de que modo as matérias são veiculadas nas páginas desse impresso. Para tanto, nossa análise busca mostrar as relações entre os gêneros jornalísticos para então classificar o objeto de estudo. A metodologia privilegia a conceituação de jornalismo, notícia, reportagem e jornalismo sensacionalista e contempla também a pesquisa de campo, com visitas in loco na redação do periódico e entrevista com seus agentes. Quanto ao método de trabalho, a pesquisa qualitativa segue o modelo teórico-crítico. Foram feitas análises morfológica e de conteúdo do corpus, para identificar, caracterizar e classificar o objeto estudado. Do ponto de vista jornalístico, os aportes teóricos estão ancorados em Marques de Melo e outros autores que construíram teoria sobre Jornalismo. No que concerne ao objeto de estudo, no segmento tabloide os resultados apontam para uma nova visão do jornalismo atual.

TEORIA E PRÁTICA DOS GÊNEROS JORNALÍSTICOS: estudo empírico dos principais diários das cinco macro-regiões brasileiras

Esta pesquisa aborda os gêneros jornalísticos praticados na imprensa contemporânea a partir da comparação dos textos publicados nos cinco maiores jornais de cada macro-região do país em relação às classificações elaboradas no ambiente acadêmico. Foram pesquisadas sete edições dos maiores jornais de cada região geográfica do Brasil - tendo como referência os números do Instituto Verificador de Circulação - em uma semana construída durante o mês de novembro e dezembro de 2006. Como metodologia, adotou-se a Análise de Conteúdo englobando referencial teórico das Ciências da Comunicação e da Linguagem a partir da classificação proposta por Marques de Melo. A análise dos dados revelou que os gêneros Informativo e Opinativo usuais na prática das redações estão contemplados nos formatos classificados da teoria. O trabalho demonstra que o gênero Utilitário está legitimado na prática e na produção acadêmica. O Interpretativo apresentou presença irrelevante nas páginas dos jornais enquanto o Diversional não foi encontrado. A análise apontou que não houve criação significativa de nenhum novo gênero no jornalismo regional impresso brasileiro.(AU)

A GÊNESE, O DESENVOLVIMENTO E A DIFUSÃO DA FOLKCOMUNICAÇÃO

Investigação sobre a gênese da teoria da Folkcomunicação, tendo por objetivo identificar suas matrizes epistemológicas e suas raízes metodológicas, bem como caracterizar sua natureza interdisciplinar, gravitando em torno das ciências da comunicação e da cultura. O estudo parte da análise do desenvolvimento dos conceitos de Luiz Beltrão, contextualizando sua ancoragem inicial na teoria do jornalismo (1967) e sua posterior ampliação para incluir as dimensões do processo social da comunicação (1980). Com base na exegese da obra seminal do fundador da Folkcomunicação, buscamos extrair as contribuições do autor para o avanço das teorias da comunicação ao adaptar dimensões de bilateralidade e de formas de expressão da cultura popular nos processos da comunicação. Realizamos, também, a análise crítica dos avanços teóricos e das estratégias metodológicas construídas pelos estudiosos que deram continuidade aos estudos de Luiz Beltrão. Em seguida, investigamos a disseminação dos conhecimentos sobre folkcomunicação no Brasil e no âmbito acadêmico internacional. O corpus analisado foi a obra de Beltrão sobre o tema, bem como, dissertações, teses, livros, artigos e comunicações cientificas, que tratam da folkcomunicação. A metodologia utilizada terá por base a pesquisa bibliográfica e documental e a análise taxonômica. O período analisado compreenderá os estudos publicados sobre a Folkcomunicação desde a obra original de Beltrão, em 1967 até 2007.

Role of organizational identification, on Implicit Leadership Theories ILTs, transformational leadership and work attitudes

This investigation explores the effects of organizational identification on employees’ Implicit Leadership Theories (ILTs) and the perception of leader behaviors. The study involved a cross-sectional survey of 439 employees from seven companies based in South Wales. Respondents completed two questionnaires that measured their organizational identification, ILTs, recognition of ILTs in their manager, manager’s leadership behaviors (transactional and transformational), and psychological reactions (job satisfaction, well-being, and turnover intentions). The level of organizational identification did not affect the prototype of an ideal work-based leader. However, high organizational identification was associated with more positive ratings on the actual manager, the extent to which their manager displayed transactional and transformational behaviors, and with more positive psychological reactions to work. Employees high in organizational identification based their judgments of their leader’s transactional and transformational behaviors on the extent to which they recognized their leader as possessing leadership traits. However, those low on organizational identification allowed their prototype of their ideal leader to bias their judgment of their actual leader’s behavior. Finally, there was partial support for the augmenting hypothesis (that tranformational leadership would predict additional variance in psychological outcomes above that predicted by transactional leadership) for those high in organizational identification but not for those low in organizational identification.

Implicit leadership theories in applied settings:factor structure, generalizability, and stability over time

The present empirical investigation had a 3-fold purpose: (a) to cross-validate L. R. Offermann, J. K. Kennedy, and P. W. Wirtz's (1994) scale of Implicit Leadership Theories (ILTs) in several organizational settings and to further provide a shorter scale of ILTs in organizations; (b) to assess the generalizability of ILTs across different employee groups, and (c) to evaluate ILTs' change over time. Two independent samples were used for the scale validation (N 1 = 500 and N 2 = 439). A 6-factor structure (Sensitivity, Intelligence, Dedication, Dynamism, Tyranny, and Masculinity) was found to most accurately represent ILTs in organizational settings. Regarding the generalizability of ILTs, although the 6-factor structure was consistent across different employee groups, there was only partial support for total factorial invariance. Finally, evaluation of gamma, beta, and alpha change provided support for ILTs' stability over time.

Applications of differential geometry to high spin field theories

The main aim of this thesis is to investigate the application of methods of differential geometry to the constraint analysis of relativistic high spin field theories. As a starting point the coordinate dependent descriptions of the Lagrangian and Dirac-Bergmann constraint algorithms are reviewed for general second order systems. These two algorithms are then respectively employed to analyse the constraint structure of the massive spin-1 Proca field from the Lagrangian and Hamiltonian viewpoints. As an example of a coupled field theoretic system the constraint analysis of the massive Rarita-Schwinger spin-3/2 field coupled to an external electromagnetic field is then reviewed in terms of the coordinate dependent Dirac-Bergmann algorithm for first order systems. The standard Velo-Zwanziger and Johnson-Sudarshan inconsistencies that this coupled system seemingly suffers from are then discussed in light of this full constraint analysis and it is found that both these pathologies degenerate to a field-induced loss of degrees of freedom. A description of the geometrical version of the Dirac-Bergmann algorithm developed by Gotay, Nester and Hinds begins the geometrical examination of high spin field theories. This geometric constraint algorithm is then applied to the free Proca field and to two Proca field couplings; the first of which is the minimal coupling to an external electromagnetic field whilst the second is the coupling to an external symmetric tensor field. The onset of acausality in this latter coupled case is then considered in relation to the geometric constraint algorithm.

Exits, entrances and entrepreneurship : an exploration of economic theories of entrepreneurship through new independent entry and infant exit

The thesis began as a study of new firm formation. Preliminary research suggested that infant death rate was considered to be a closely related problem and the search was for a theory of new firm formation which would explain both. The thesis finds theories of exit and entry inadequate in this respect and focusses instead on theories of entrepreneurship, particularly those which concentrate on entrepreneurship as an agent of change. The role of information is found to be fundamental to economic change and an understanding of information generation and dissemination and the nature and direction of information flows is postulated to lead coterminously to an understanding of entrepreneurhsip and economic change. The economics of information is applied to theories of entrepreneurhsip and some testable hypotheses are derived. The testing relies on etablishing and measuring the information bases of the founders of new firms and then testing for certain hypothesised differences between the information bases of survivors and non-survivors. No theory of entrepreneurship is likely to be straightforwardly testable and many postulates have to be established to bring the theory to a testable stage. A questionnaire is used to gather information from a sample of firms taken from a new micro-data set established as part of the work of the thesis. Discriminant Analysis establishes the variables which best distinguish between survivors and non-survivors. The variables which emerge as important discriminators are consistent with the theory which the analysis is testing. While there are alternative interpretations of the important variables, collective consistency with the theory under test is established. The thesis concludes with an examination of the implications of the theory for policy towards stimulating new firm formation.

A critical evaluation of theories of nationalism

This thesis considers the main theoretical positions within the contemporary sociology of nationalism. These can be grouped into two basic types, primordialist theories which assert that nationalism is an inevitable aspect of all human societies, and modernist theories which assert that nationalism and the nation-state first developed within western Europe in recent centuries. With respect to primordialist approaches to nationalism, it is argued that the main common explanation offered is human biological propensity. Consideration is concentrated on the most recent and plausible of such theories, sociobiology. Sociobiological accounts root nationalism and racism in genetic programming which favours close kin, or rather to the redirection of this programming in complex societies, where the social group is not a kin group. It is argued that the stated assumptions of the sociobiologists do not entail the conclusions they draw as to the roots of nationalism, and that in order to arrive at such conclusions further and implausible assumptions have to be made. With respect to modernists, the first group of writers who are considered are those, represented by Carlton Hayes, Hans Kohn and Elie Kedourie, whose main thesis is that the nation-state and nationalism are recent phenomena. Next, the two major attempts to relate nationalism and the nation-state to imperatives specific either to capitalist societies (in the `orthodox' marxist theory elaborated about the turn of the twentieth century) or to the processes of modernisation and industrialisation (the `Weberian' account of Ernest Gellner) are discussed. It is argued that modernist accounts can only be sustained by starting from a definition of nationalism and the nation-state which conflates such phenomena with others which are specific to the modern world. The marxist and Gellner accounts form the necessary starting point for any explanation as to why the nation-state is apparently the sole viable form of polity in the modern world, but their assumption that no pre-modern society was national leaves them without an adequate account of the earliest origins of the nation-state and of nationalism. Finally, a case study from the history of England argues both the achievement of a national state form and the elucidation of crucial components of a nationalist ideology were attained at a period not consistent with any of the versions of the modernist thesis.

From ideal to real:a longitudinal study of the role of implicit leadership theories on leader-member exchanges and employee outcomes

The results of the present longitudinal study demonstrate the importance of implicit leadership theories (ILTs) for the quality of leader-member exchanges (LMX) and employees' organizational commitment, job satisfaction, and well-being. Results based on a sample of 439 employees who completed the study questionnaires at 2 time points showed that the closer employees perceived their actual manager's profile to be to the ILTs they endorsed, the better the quality of LMX. Results also indicated that the implicit-explicit leadership traits difference had indirect effects on employee attitudes and well-being. These findings were consistent across employee groups that differed in terms of job demand and the duration of manager-employee relation, but not in terms of motivation. Furthermore, crossed-lagged modeling analyses of the longitudinal data explored the possibility of reciprocal effects between implicit-explicit leadership traits difference and LMX and provided support for the initially hypothesized direction of causal effects.

Assessing the efficacy of structural merger remedies:choosing between theories of harm?

This paper shows that many structural remedies in a sample of European merger cases result in market structures which would probably not be cleared by the Competition Authority (CA) if they were the result of merger (rather than remedy).This is explained by the fact that the CA’s objective through remedy is to restore premerger competition, but markets are often highly concentrated even before merger. If so, the CA must often choose between clearing an ‘uncompetitive’merger, or applying an unsatisfactory remedy. Here, the CA appears reluctant to intervene against coordinated effects, if doing so enhances a leader’s dominance.

Assessing the efficacy of structural merger remedies:choosing between theories of harm?

Previous empirical assessments of the effectiveness of structural merger remedies have focused mainly on the subsequent viability of the divested assets. Here, we take a different approach by examining how competitive are the market structures which result from the divestments. We employ a tightly specified sample of markets in which the European Commission (EC) has imposed structural merger remedies. It has two key features: (i) it includes all mergers in which the EC appears to have seriously considered, simultaneously, the possibility of collective dominance, as well as single dominance; (ii) in a previous paper, for the same sample, we estimated a model which proved very successful in predicting the Commission’s merger decisions, in terms of the market shares of the leading firms. The former allows us to explore the choices between alternative theories of harm, and the latter provides a yardstick for evaluating whether markets are competitive or not – at least in the eyes of the Commission. Running the hypothetical post-remedy market shares through the model, we can predict whether the EC would have judged the markets concerned to be competitive, had they been the result of a merger rather than a remedy. We find that a significant proportion were not competitive in this sense. One explanation is that the EC has simply been inconsistent – using different criteria for assessing remedies from those for assessing the mergers in the first place. However, a more sympathetic – and in our opinion, more likely – explanation is that the Commission is severely constrained by the pre-merger market structures in many markets. We show that, typically, divestment remedies return the market to the same structure as existed before the proposed merger. Indeed, one can argue that any competition authority should never do more than this. Crucially, however, we find that this pre-merger structure is often itself not competitive. We also observe an analogous picture in a number of markets where the Commission chose not to intervene: while the post-merger structure was not competitive, nor was the pre-merger structure. In those cases, however, the Commission preferred the former to the latter. In effect, in both scenarios, the EC was faced with a no-win decision. This immediately raises a follow-up question: why did the EC intervene for some, but not for others – given that in all these cases, some sort of anticompetitive structure would prevail? We show that, in this sample at least, the answer is often tied to the prospective rank of the merged firm post-merger. In particular, in those markets where the merged firm would not be the largest post-merger, we find a reluctance to intervene even where the resulting market structure is likely to be conducive to collective dominance. We explain this by a willingness to tolerate an outcome which may be conducive to tacit collusion if the alternative is the possibility of an enhanced position of single dominance by the market leader. Finally, because the sample is confined to cases brought under the ‘old’ EC Merger Regulation, we go on to consider how, if at all, these conclusions require qualification following the 2004 revisions, which, amongst other things, made interventions for non-coordinated behaviour possible without requiring that the merged firm be a dominant market leader. Our main conclusions here are that the Commission appears to have been less inclined to intervene in general, but particularly for Collective Dominance (or ‘coordinated effects’ as it is now known in Europe as well as the US.) Moreover, perhaps contrary to expectation, where the merged firm is #2, the Commission has to date rarely made a unilateral effects decision and never made a coordinated effects decision.