A colisão de buracos negros é uma das fontes mais importantes de ondas gravitacionais e, em geral, a emissão anisotrópica da radiação causa um recuo do objeto final. Este cenário já é conhecido há décadas, mas foi somente com o recente avanço na relatividade numérica que as velocidades finais dos objetos radiantes foram computadas com precisão. Os valores encontrados podem ser altos o suficiente para exercerem um importante papel no crescimento de buracos negros super massivos via coleção de galáxias e na abundância de núcleos galáticos ativos contendo buracos negros. Este é um autêntico efeito da não linearidade de Relatividade Geral e esta tese fornece uma nova metodologia estudar alguns aspectos da dinâmica da colisão de buracos negros. Consideramos o horizonte como uma tela canônica que codifica as informações da evolução temporal do espaço-tempo. Com esta hipótese, fenômenos como o anti-kick, isto é, uma súbita desaceleração do sistema antes de atingir a velocidade final, são explicado em termos da dissipação das deformações do horizonte. Estudamos primeiramente o Espaço-tempo de Robinson-Trautman. Uma das solução mais simples das equações de Einstein, esta métrica nos fornece um poderoso modelo para investigar tanto a perda de massa quanto o recuo do objeto final. Mostramos que, quando as configurações iniciais tem simetria especular, a massa do buraco negro remanescente e a energia irradiada são completamente determinadas pela condição inicial. Com isso, obtemos as expressões analíticas dos resultados numéricos obtidos anteriormente na literatura. Além disto, com o auxilio do método espectral de Galerkin, analisamos o regime não linear das equações envolvidas e verificamos que se pode estimar a velocidade de recuo final com boa precisão a partir de medidas da assimetria da condição inicial. Introduzimos na seqüência a curvatura efetiva como uma medida das deformações intrínsecas ao horizonte. Além de considerar as deformações gerais, ela também inclui as diferenças entre os hemisférios norte e sul. No espaço-tempo de Robinson-Trautman, essa quantidade se correlaciona de uma forma injetora com a velocidade final. Para superar algumas limitações dessa solução, aplicamos o mesmo procedimento nos resultados da simulação numérica de uma colisão head-on. Neste caso, a curvatura efetiva, está na realidade, correlacionada com a aceleração do sistema. Refinamentos e generalizações desta técnica são também discutidos e propostos para trabalhos futuros. / Colliding black holes are one of the most important sources of gravitational waves and the anisotropic emission of the radiation generally causes the recoil of the final hole. This scenario has been known for decades, but it is only thanks to the recent progress in numerical relativity that the final velocity have been accurately computed. The values found can be large enough to play an important role in the growth of supermassive black holes via mergers of galaxies and on the number of galaxies containing them. This is a genuine nonlinear effect of general relativity and this thesis provides a new methodology to study some features on the dynamics of the collision. We propose that the horizon is a canonical screen, which encodes he information of its surroundings. With this assumption, phenomena such as the anti-kick, namely the sudden deceleration before reaching the final velocity, are explained in terms of the dissipation of the horizons deformation. We first study the Robinson-Trautman spacetime. One of the simplest solutions of Einsteins equations, it provides us with a powerful toymodel to investigate both the mass loss of the system and the recoil of the final object. We show that, for the case of reflectionsymmetric initial configurations, the mass of the remnant black-hole and the total energy radiated away are completely determined by the initial data, allowing us to obtain analytical expressions for some numerical results that had appeared in the literature. Moreover, by using the Galerkin spectral method to analyze the non-linear regime of the equations involved, we found that the recoil velocity can be estimated with good accuracy from some symmetry measures of the initial data. Then we introduce the effective urvature as a measure of intrinsic deformations on the horizon. Not only does it account for overall deformation, but also for the differences on the north and south hemispheres. In the Robinson-Trautman spacetime, this quantity correlates in an injective way with the final velocity. To overcome some caveats of this solutions, we apply the same procedure to the results given by numerical simulations of a head-on collision. In the case, the effective curvature is actually correlated with the acceleration of the system. Further improvement and generalizations of this technic is also discussed and proposed for future work.

Orientador: Luiz C. Marques Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / Made available in DSpace on 2018-07-21T17:20:11Z (GMT). No. of bitstreams: 1 Zwilling_Carin_M.pdf: 5939115 bytes, checksum: 4286fdb7c47650ab874a6b3a914c7954 (MD5) Previous issue date: 1996 / Resumo: Não informado. / Abstract: Not informed. / Mestrado / Mestre em História

"Edge Effects: Poetry, Place, and Spiritual Practices” focusses on the intersection of the environmental and religious imaginations in the work of five West Coast poets: Robinson Jeffers, Theodore Roethke, Robert Hass, Denise Levertov, and Jan Zwicky. My research examines the selected poems for their reimagination of the sacred perceived through attachments to particular places. For these writers, poetry is a constitutive practice, part of a way of life that includes desire for wise participation in the more-than-human community. Taking into account the poets’ critical reflections and historical-cultural contexts, along with a range of critical and philosophical sources, the poetry is examined as a discursive spiritual exercise. It is seen as conjoined with other focal practices of place, notably meditative walking and attentive looking and listening under the influence of ecospiritual eros. My analysis attends to aesthetics of relinquishment, formal strategies employed to recognize and accept finitude and the non-anthropocentric nature of reality, along with the complementary aesthetics of affirmation, configuration of the goodness of the whole. I identify an orienting feature of West Coast place, particular to each poet, that recurs as a leitmotif for engagement of such aesthetics and related practices. In chapter one, I consider a group of Jeffers’s final poems as part of a project he designated “our De Natura,” attending especially to his affinity for stones and stars. In chapter two, I investigate both Roethke’s and Hass’s configurations of ecospiritual eros in accord with their fascination for flora, while in chapter three, I employ the concepts of “aura” and “resonance” to explicate Levertov’s meditations on the “coming and going” Mount Rainier-Tacoma and Zwicky’s reflective iterations of the sea. / Graduate / 2019-04-04

The purpose of this thesis is to examine the history in English literature of the relationship between King Arthur, Guinevere, and Lancelot, in order to show how various authors have enriched the legend by developing the psychological potential of the chief characters, and by projecting the standards of their respective ages into their versions of the story. Special emphasis has been placed on the work of Sir Thomas Malory, Alfred Tennyson, E.A. Robinson, and T.H. White. The Arthurian legend is particularly appropriate for such a comparative study. It has received the attention of English writers for eight centuries, and, for the past hundred years, of writers in America as well. In the fifteenth century Malory used the legend to argue for a strong monarchy, and to remind his aristocratic countrymen of the neglected ideals of chivalry; in the nineteenth century Tennyson hoped that the re-telling of the story for its elements of moral and spiritual allegory would inspire the Victorians to rise above the materialism and sensuality which to him were signs of the times; early in the twentieth century Edwin Arlington Robinson suggested a comparison between the disintegration of Camelot and the disruption of European society after World War I, and he questioned the traditionally accepted greatness of Arthur and his kingdom; in the last decade Terence Hanbury White has seen that the problem facing King Arthur also confronts the strife-torn twentieth century how can the energies of men be harnessed for constructive rather than destructive action? The adultery between Guinevere and Lancelot has been made the focal point of this study because it involves the three best-known characters of the legend, and because it has attracted the interest of writers more than has any other element of the Arthuriad, particularly in the past one hundred years. / Arts, Faculty of / English, Department of / Graduate

"Storied Voices in Native American Texts: Harry Robinson, Thomas King, James Welch and Leslie Marmon Silko" approaches Native American literatures from within an interdisciplinary framework that complicates traditional notions o f literary "origins" and canon. It situates the discussion of Native literatures in a Native American context, suggesting that contemporary Native American writing has its roots in Native oral storytelling traditions. Each of these authors draws on specific stories and histories from his or her Native culture. They also draw on European elements and contexts because these are now part o f Native American experience. I suggest that Native oral tradition is already inherently novelistic, and the stories that lie behind contemporary Native American writing explicitly connect past and present as aspects o f current Native reality. Contemporary Native American writers are continuing an on-going and vital storytelling tradition through written forms. A comparison of the texts o f a traditional Native storyteller, Robinson, with the highly literate novels of King, Welch and Silko, shows how orally told stories connect with the process o f writing. Robinson's storytelling suggests how these stories "theorize" the world as he experiences it; the Native American novel continues to theorize Native experience in contemporary times. Native writers use culturally specific stories to express an on-going Native history. Their novels require readers to examine their assumptions about who is telling whose story, and the traditional distinctions made between fact and fiction, history and story. King's Green Grass. Running Water takes stories from Western European literary traditions and Judeao-Christian mythology and presents them as part of a Native creation story. Welch's novel Fools Crow re-writes a particular episode from history, the Marias River Massacre, from a Blackfeet perspective. Silko's Almanac of the Dead recreates the Mayan creation story o f the Popol Vuh in the context o f twentiethcentury American culture. Each of these authors maintains the dialogic fluidity of oral storytelling performance in written forms and suggests that stories not only reflect the world, but that they create it in the way that Robinson understands storytelling as a form of theory. / Arts, Faculty of / English, Department of / Graduate

La théorie de la relativité générale décrit l'effet de la gravitation en termes de géométrie des espaces-temps. La courbure des variétés lorentzienne est liée à l'énergie et l'évolution de la matière (ou du vide) par les équations d'Einstein, un système d'équations différentielles non-linéaires. Dans les années 1950, l'existence locale de solutions des équations d'Einstein a été établie. Motivé par ce résultat, j'étudie l'évolution ainsi que la régularité des espaces-temps. Il est démontré que certaines estimations d'énergie peuvent être contrôlées par des limites unilatérales portant uniquement sur la géométrie. Les estimations de l'énergie Bel-Robinson, par exemple, sont indispensables pour le calcul des critères d'effondrement pour les solutions des équations d'Einstein. Comme un important espace-temps, des modèles astrophysiques avec des sources de fluides parfaits sont considérés. Une théorie d'existence de solutions à symétrie sphérique pour l'équations Einstein-Euler est présenté et on identifie une classe de données initiales non-piégées qui conduit à la formation dynamique de surfaces piégées. Pour permettre des ondes de choc, des solutions à variation bornée sont considérées. Dans ce cadre de là et dans d'autres domaines de la relativité générale, il est crucial de comprendre si et comment la régularité des métriques influe sur la géométrie des espaces-temps. Je propose aussi quelques résultats généraux sur les métriques riemanniennes continues et sur l'algèbre des fonctions généralisées. Cette thèse montre donc que l'espace-temps de faible régularité présentent un large éventail de phénomènes intéressants au cours de leur évolution. / The general theory of relativity describes the effect of gravitation in terms of the geometry of spacetimes. The curvature of Lorentzian manifolds is related to the energy and momentum of matter (or vacuum) by the Einstein equations, a system of nonlinear partial differential equations. In the 1950s the initial value formulation and local existence of solutions to the Einstein equations were established. As of yet the global structure of spacetimes is much less understood. Motivated by this I investigate the evolution as well as the regularity of spacetimes. I show that certain energy estimates can be controlled by one-sided bounds on the geometry only. Estimates of the Bel-Robinson energy, for example, play a crucial role in the derivation of breakdown criteria for solutions of the vacuum Einstein equations. As an important astrophysical model spacetimes with perfect fluid sources are considered. An existence theory for spherically symmetric solutions to the Einstein-Euler equations is presented, and, above all, I identify for the first time a class of untrapped initial data that leads to the dynamical formation of trapped surfaces. To allow for shock waves, solutions are regarded to be of bounded variation. The distributional framework is essential here and in other areas of general relativity, and it is crucial to understand if and how the regularity of metrics influences the geometry of spacetimes. I account for this by deriving some general results on continuous Riemannian metrics and algebras of generalized functions. This thesis thus illustrates that spacetimes of low regularity exhibit a wide range of interesting phenomena during their evolution.

Der Zusammenhang zwischen Lohnhöhe einerseits und Profit bzw. Profitrate andererseits gehört traditionell zur Grundlagenforschung der ökonomischen Theorie. In der kapitaltheoretischen Kontroverse der jüngeren Vergangenheit spielen Kurven, die diesen Zusammenhang wiedergeben, eine bedeutende Rolle. Hier geht es indes weniger um deren formale Eigenschaften, sondern eher darum, ihren ökonomischen Gehalt freizulegen und auf offene Fragen hinzuweisen.

This thesis deals with changes in the presidential office in Ireland during the presidency of Mary Robinson between 1990-1997. The presidential office holds very few powers and it has been always perceived more as ceremonial and symbolic function. Robinson had been very active during her reign since the beginning, thus breaking the precedence given by former presidents. The goal of this thesis is to define both, particular tools and mechanisms which Robinson had used to transform the nature of the office. Moreover, the thesis aims to examine whether Robinson stayed within the constitutional boundaries. My hypothesis states, that main tools which Robinson used to transform the presidency, are the different forms of activism. The first part the research focuses on the analysis of the constitutional development of presidential office as well as the powers of president listed in the constitution. Further, in the thesis, I focused on Robinson's activity not only during her presidency but also on the prior period as the presidential campaign or Robinson's professional career. This is important to define particular tools and mechanisms which Robinson used to change the presidency. The main findings of my thesis reveal the tools which Robinson used to transform the office - activism and symbolism. Both of...

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In The Machine in the Garden: Technology and the Pastoral Idea in America, Leo Marx “evaluates the uses of the pastoral ideal in the interpretation of American experience” (Marx 4). While Marx explores ways that pastoralism has been impacted by factors such as industrialism, it is the purpose of this project to explore Marx’s assertion regarding the presence of the figurative and literal machine within the poetry of Robinson Jeffers. Jeffers’ poetry is generally located within the landscapes of California. His lyric poetry has a distinct connection to the land and is driven by inhumanism, which works to shift the “emphasis and significance from man to not-man…” (Oelschlaeger 246). Jeffers’ machine like elements highlight the relationship between the natural world and humanity’s intrusion; in doing so, Jeffers furthers Marx’s supposition that American literature continues to be impacted by the machine, by “forces working against the dream of pastoral fulfillment” (Marx 358).