1,720,958 research outputs found
Quantum corpuscular approach to solutions in gravity and field theory
Get PDFWe formulate a quantum theory of classical solutions in gravity and field theory in terms of a large number of constituent degrees of freedom. The description is realized in two different ways.
In the first part we introduce the so-called auxiliary current description. The basic idea is to represent the true quantum state of the solution one considers in terms of a multi- local composite operator of the fields of the microscopic theory. Although the approach is completely general, we will be mostly interested in representing black holes as bound states of a large number of gravitons. We show how the mass of the black hole arises microscopically as a collective effect of N gravitons composing the bound state. For that purpose we compute observables associated to the black hole interior such as the constituent density of gravitons and their energy density, respectively. As a next step, it is shown how these observables can be embedded within S-matrix processes. In particular, it is demonstrated that an outside observer has access to the black hole interior doing scattering experiments. Measuring the cross section for the scattering of particles on black holes, the outside observer is sensitive to the distribution of gravitons in the black hole. Possible implications concerning the information paradox are discussed. Finally, we show how geometric concepts, and in particular the Schwarzschild solution emerge as an effective description derived from our construction.
In the second part, an alternative approach based on coherent states in presented. First, we apply our reasoning to solitons in field theory. In particular, we explicitly show how well-known properties of solitons such as interactions, false vacuum decay or conservation of topological charge follow easily from the basic properties of coherent states. Secondly, we develop in detail a similar quantum picture of instantons. Since instantons can be understood in terms of solitons in one more spatial dimension evolving in Euclidean time, a coherent state description of the latter implies a similar description of the former. Using the coherent state picture we develop a novel quantum mechanical understanding of the physics of instanton-induced transitions and the concept of resurgence. Finally, we consider solitons in supersymmetric theories. It is shown that the corpuscular effects lead to a novel mechanism of supersymmetry breaking which can never be accounted for in the semi- classical approach.
In the last part of the thesis we resolve anti-de Sitter (AdS) space-time as a coherent state. On the one hand, we explain how well-known holographic and geometric properties can easily be understood in terms of the occupation number of gravitons in the state. On the other hand, we explicitly compute corpuscular corrections to the scalar propagator in AdS. Furthermore, it is shown that corpuscular effects lead to deviations from thermality an Unruh observer in AdS measures.Wir formulieren eine Quantentheorie von L ̈osungen in Gravitation und Feldtheorie basierend auf einer großen Anzahl von Konstituentenfreiheitsgraden. Solch eine Beschreibung wird auf zwei verschiedene Arten realisiert.
Im ersten Teil stellen wir die sogenannte Hilfsstrombeschreibung vor. Die grundlegende Idee besteht darin, den wahren quantenmechanischen Zustand der Lo ̈sung die man betra- chtet, durch einen multilokalen zusammengesetzten Operator der Felder der mikroskopis- chen Theorie zu representieren. Obwohl dieser Ansatz komplett allgemein ist, werden wir haupt ̈achlich daran interessiert sein, schwarze Lo ̈cher als gebundene Gravitonzust ̈ande aufzufassen. Wir zeigen, dass die Masse des schwarzen Lochs mikroskopisch gesehen ein kollektiver Effekt von N Gravitonen ist, welche das schwarze Loch zusammensetzen. Um dies zu demonstrieren, berechnen wir Observablen, welche mit dem Inneren des schwarzen Lochs in Zusammenhang stehen, wie die Konstituenten- oder die Energiedichte von Gravi- tonen. Als na ̈chster Schritt wird gezeigt, wie diese Observablen in S-Matrix Prozesse eingebettet werden k ̈onnen. Insbesondere wird gezeigt, dass ein Beobachter außerhalb des schwarzen Lochs Zugang zu dessen Innerem hat indem er Streuexperimente durchfu ̈hrt. Durch Messung des Wirkungsquerschnittes fu ̈r die Streuung von Teilchen am schwarzen Loch, ist ein außenstehender Beobachter sensitiv auf die Verteilung von Gravitonen im schwarzen Loch. Mo ̈gliche Implikationenen dieses Resultates im Bezug auf das Informa- tionsparadoxon werden diskutiert. Schließlich zeigen wir, wie geometrische Konzepte, und insbesondere die Schwarzschild-Lo ̈sung, sich als effektive Beschreibung aus unserer Kon- struktion herleiten lassen.
Im zweiten Teil wird in alternativer Ansatz basierend auf koha ̈renten Zust ̈anden pra ̈sen- tiert. Zuerst wenden wir diese Logik auf Solitonen in Feldtheorie an. Insbesondere zeigen wir explizit, wie wohlbekannte Eigenschaften von Solitonen zum Beispiel deren Wechsel- wirkung, Zerfall des falschen Vakuums, oder Erhaltung topologischer Ladung als simple Konsequenz der grundlegenden Eigenschaften von koha ̈renten Zusta ̈nden folgen. Darauf folgend entwickeln wir ein a ̈hnliches quantenmechanisches Bild von Instantonen. Da In- stantonen als Solitonen in einer weiteren r ̈aumlichen Dimension verstanden werden ko ̈nnen, welche sich in euklidischer Zeit entwickeln, impliziert eine Beschreibung von Solitonen, basierend auf koha ̈renten Zust ̈anden, dass Instantonen auf eine a ̈hnliche Weise beschrieben werden sollten. Darauf aufbauend entwickeln wir ein neuartiges quantenmechanisches Verst ̈andnis im Bezug auf die Physik von Instanton-induzierten U ̈berga ̈ngen und dem Konzept von ”Resurgence”. Zum Schluss betrachten wir Solitonen in supersymmetrischen
Theorien. Es wird gezeigt, dass die korpuskula ̈ren Effekte zu einem neuen Supersym- metriebrechungsmechanismus fu ̈hren, welcher niemals in der semi-klassischen Behandlung gesehen werden kann.
In letzten Abschnitt der Arbeit lo ̈sen wir Anti-de Sitter (AdS) als koha ̈renten Zustand auf. Einerseits werden wir erkla ̈ren, wie wohlbekannte holographische und geometrische Eigenschaften einfach verstanden werden ko ̈nnen durch die Besetzungszahl von Gravitonen im Zustand. Andererseits berechnen wir explizit korpuskula ̈re Korrekturen zum skaralen Propagator in AdS. Zusa ̈tzlich wird gezeigt, dass korpuskula ̈re Effekte zu Abweichungen der Thermalit ̈at fu ̈hren, die ein Unruh-Beobachter in AdS misst
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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