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Duality
Terms modified by Duality Selected AbstractsDUALITY IN OPTIMAL INVESTMENT AND CONSUMPTION PROBLEMS WITH MARKET FRICTIONSMATHEMATICAL FINANCE, Issue 2 2007I. Klein In the style of Rogers (2001), we give a unified method for finding the dual problem in a given model by stating the problem as an unconstrained Lagrangian problem. In a theoretical part we prove our main theorem, Theorem 3.1, which shows that under a number of conditions the value of the dual and primal problems is equal. The theoretical setting is sufficiently general to be applied to a large number of examples including models with transaction costs, such as Cvitanic and Karatzas (1996) (which could not be covered by the setting in Rogers [2001]). To apply the general result one has to verify the assumptions of Theorem 3.1 for each concrete example. We show how the method applies for two examples, first Cuoco and Liu (1992) and second Cvitanic and Karatzas (1996). [source] DUALITY WITH SECTOR-SPECIFIC EXTERNALITIES UNDER SOCIAL CONSTANT RETURNS,THE JAPANESE ECONOMIC REVIEW, Issue 4 2006KAZUO NISHIMURA We develop dual approaches to quantity and price relationships of production in a general multisectoral model with sector-specific externalities. The production of each good exhibits socially constant returns to scale but privately decreasing returns. We find that the Stolper-Samuelson theorem holds for factor intensity ranking from the social perspective and that the Rybczynski theorem holds for factor intensity ranking from the private perspective. The price-output dual fails to hold in general. Moreover, we re-establish the Heckscher-Ohlin theorem in the two-sector case, as well as the factor endowment,factor price and price-output comparative statics in the high-dimension case under proper conditions. [source] Language, Duality, and Bastardy in English Renaissance DramaENGLISH LITERARY RENAISSANCE, Issue 2 2004Nicholas Crawford By figuring language and thoughts as illegitimate, these locutions displace or confuse a discourse of blood lineage and social status with one that registers uneasiness about the derivation of ideas and their expression. This fantasized genealogy of bastard conceptions and their linguistic progeny signals the mind's growing alienation from the body and reveals an incipient Cartesian separation of the two. As the theater provides a spectacle of words bodied forth, it is often the drama of the early modern period that most strikingly enacts this developing duality so characteristic of modern subjectivity: the movement of language toward a realm imagined to be incorporeal. [source] Toric duality, Seiberg duality and Picard-Lefschetz transformationsFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 7-8 2003S. Franco Toric Duality arises as an ambiguity in computing the quiver gauge theory living on a D3-brane which probes a toric singularity. It is reviewed how, in simple cases Toric Duality is Seiberg Duality. The set of all Seiberg Dualities on a single node in the quiver forms a group which is contained in a larger group given by a set of Picard-Lefschetz transformations. This leads to elements in the group (sometimes called fractional Seiberg Duals) which are not Seiberg Duality on a single node, thus providing a new set of gauge theories which flow to the same universality class in the Infra Red. [source] The Philosophy of Halfness and the Philosophy of Duality: Julia Ward Howe and Ednah Dow CheneyHYPATIA, Issue 2 2004THERESE B. DYKEMANArticle first published online: 9 JAN 200 Julia Ward (1819,1910) and Ednah Dow littlehale (1824,1904), lifelong friends, wrote and lectured on many of the same issues, traveled across the country to lend support to causes, and taught together at the Concord School of Philosophy. Despite their close association and mutual efforts on similar issues, I argue that their philosophical principles were essentially different, in particular their approaches to an understanding of God, society, the sexes, art, and science. [source] Duality and eventually periodic systemsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 13 2005M. Farhood Abstract This paper employs semidefinite programming duality theory to develop new alternative linear matrix inequality (LMI) tools for eventually periodic systems. These tools are then utilized to rederive an important version of the Kalman,Yakubovich,Popov (KYP) Lemma for such systems, and further give new synthesis results. Copyright © 2005 John Wiley & Sons, Ltd. [source] Duality revisited: Construction of fractional frequency distributions based on two dual Lotka lawsJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 10 2002L. Egghe Fractional frequency distributions of, for example, authors with a certain (fractional) number of papers are very irregular and, therefore, not easy to model or to explain. This article gives a first attempt to this by assuming two simple Lotka laws (with exponent 2): one for the number of authors with n papers (total count here) and one for the number of papers with n authors, n , ,. Based on an earlier made convolution model of Egghe, interpreted and reworked now for discrete scores, we are able to produce theoretical fractional frequency distributions with only one parameter, which are in very close agreement with the practical ones as found in a large dataset produced earlier by Rao. The article also shows that (irregular) fractional frequency distributions are a consequence of Lotka's law, and are not examples of breakdowns of this famous historical law. [source] Duality, income and substitution effects for the competitive firm under price uncertaintyMANAGERIAL AND DECISION ECONOMICS, Issue 4 2005Carmen F. Menezes This paper uses duality theory to decompose the total effect on the competitive firm's output of an increase in the riskiness of output price into income and substitution effects. Properties of preferences that control the sign of each effect are identified. The analysis extends to the general class of quasi-linear decision models in which the payoff is linear in the random variable. Copyright © 2005 John Wiley & Sons, Ltd. [source] Labor Market Duality and Leisure Industries in Spain: Quality of Life Versus Standard of LivingAMERICAN JOURNAL OF ECONOMICS AND SOCIOLOGY, Issue 4 2008Juan L. Paramio We discuss the effects that the emergence of the new postindustrial form of flexible capitalist organization has on the Spanish labor market and, by extension, on the working life of two representative groups of employees characterized by their casual and stable working conditions. This brings a growing duality in the labor market, where individuals who cannot escape casual employment coexist with those enjoying long-term contracts. This concern includes how these changes affect the nature and the ways in which these particular groups understand quality of life and standard of living, which in turn serves to call into question the "end of work" and the expected "leisure society." In addition, we highlight several circumstances that illustrate a decay in job quality and working conditions, particularly the increase in working hours. Parallel to this process we identify a work-and-spend behavior, resulting in overspent families that exhibit financial fragility and give up quality of life, associated with more free time, for higher living standards, which demand an increasing job commitment. Free time from work has become a scarce resource in Spain, and for those individuals belonging to what is known as the "new leisure class," it is associated with high-spending leisure activities, which has increased the economic importance of leisure industries. [source] Self and Self-Consciousness: Aristotelian Ontology and Cartesian DualityPHILOSOPHICAL INVESTIGATIONS, Issue 2 2009Andrea Christofidou The relationship between self-consciousness, Aristotelian ontology, and Cartesian duality is far closer than it has been thought to be. There is no valid inference either from considerations of Aristotle's hylomorphism or from the phenomenological distinction between body and living body, to the undermining of Cartesian dualism. Descartes' conception of the self as both a reasoning and willing being informs his conception of personhood; a person for Descartes is an unanalysable, integrated, self-conscious and autonomous human being. The claims that Descartes introspectively encounters the self and that the Cartesian extent of inner space is self-contained are profound errors, distortions through the lenses of modern theories. [source] Remarks on Duality in Graph Spaces of First-Order Linear OperatorsPROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2006Max JensenArticle first published online: 4 DEC 200 Graph spaces provide a setting alternative to Sobolev spaces and BV spaces, which is suitable for the analysis of first-order linear boundary value problems such as Friedrichs systems. Besides investigations of the well-posedness of the continuous problem there is also an increasing interest in the error analysis of finite element methods within a graph space framework. In this text we elucidate various methods for an explicit representation of dual spaces of graph spaces. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Duality between constraints and gauge conditionsANNALEN DER PHYSIK, Issue 7-8 2007M.N. Stoilov Abstract There are two important sets of seemingly absolutely different objects in any gauge theory: the set of constraints, which generate the local symmetry and the set of gauge conditions, which fix this symmetry; the first one is determined by the Lagrangean of the model, the second is a matter of choice. However, in the transition amplitude constraints and gauge conditions participate in exactly the same way. This suggests the possibility for existence of a model with the same transition amplitude and in which gauge conditions and constraints are interchanged. We investigate the conditions that gauge fixing terms should satisfy so that this dual picture is allowed. En route, we propose to add new terms in the constraints which would generate the gauge transformation of the Lagrange multipliers and construct two BRST charges , one, as usual, for the constraints, and one for the gauge conditions. [source] Preliminary Insights into the Constitution of a Tibetan Buddhist Monastery through Autoethnographic Reflections on the Dual/Nondual Mind DualityANTHROPOLOGY OF CONSCIOUSNESS, Issue 2 2008BORIS H. J. M. BRUMMANS ABSTRACT In this autoethnographic essay, I reflect on my brief personal experiences of conducting field research on ways in which way a small group of Tibetan Buddhist monks enact a monastic total institution in Ladakh, India. More specifically, I analyze my experiences in view of the relationship between dual and nondual mind, as discussed by Henry Vyner (2002) in Anthropology of Consciousness, and use this analysis to develop preliminary insights into the ways in which a Tibetan Buddhist monastery is constituted. [source] Similarity, Isomorphism or Duality?BRITISH JOURNAL OF MANAGEMENT, Issue 4 2008Recent Survey Evidence on the Human Resource Management Policies of Multinational Corporations There is considerable debate as to the determinants of the human resource policies of human resource management: do they reflect national institutional or cultural realities, emerging common global practices, parent country effects or the dual effects of transnational and national realities? We use an extensive international database to explore these differences, assessing variations in a range of human resource practices. We find new evidence of national differences in the manner in which indigenous firms manage their people, but also evidence of a similarity in practice amongst multinational corporations. In other words, multinational corporations tend to manage their human resources in ways that are distinct from those of their host country; at the same time, country of origin effects seem relatively weak. Whilst there is some evidence of common global practices, sufficient diversity in practice persists to suggest that duality theories may provide the most appropriate explanation. [source] Generalizations of the AdS/CFT correspondence,FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 8 2004I. Kirsch Abstract We consider generalizations of the AdS/CFT correspondence in which probe branes are embedded in gravity backgrounds dual to either conformal or confining gauge theories. These correspond to defect conformal field theories (dCFT) or QCD-like theories with fundamental matter, respectively. Moreover, starting from the dCFT we discuss the deconstruction of intersecting M5-branes and M-theory. We obtain the following results: i) Holography of defect conformal field theories. We consider holography for a general D3-Dp brane intersection in type IIB string theory (p , {3,5,7}). The corresponding near-horizon geometry is given by a probe AdS-brane in AdS5 × S5. The dual defect conformal field theory describes ,, = 4 super Yang-Mills degrees of freedom coupled to fundamental matter on a lower-dimensional space-time defect. We derive the spectrum of fluctuations about the brane embedding and determine the behaviour of correlation functions involving defect operators. We also study the dual conformal field theory in the case of intersecting D3-branes. To this end, we develop a convenient superspace approach in which both two- and four-dimensional fields are described in a two-dimensional (2,2) superspace. We show that quantum corrections vanish to all orders in perturbation theory, such that the theory remains a (defect) conformal field theory when quantized. ii) Flavour in generalized AdS/CFT dualities. We present a holographic non-perturbative description of QCD-like theories with a large number of colours by embedding D7-brane probes into two non-supersymmetric gravity backgrounds. Both backgrounds exhibit confinement of fundamental matter and a discrete glueball and meson spectrum. We numerically compute the quark condensate and meson spectrum associated with these backgrounds. In the first background, we find some numerical evidence for a first order phase transition at a critical quark mass where the D7 embedding undergoes a geometric transition. In the second, we find a chiral symmetry breaking condensate as well as the associated Goldstone boson. iii) Deconstruction of extra dimensions. We apply the deconstruction method to the dCFT of intersecting D3-branes to obtain a field theory description for intersecting M5-branes. The resulting theory corresponds to two six-dimensional (2,0) superconformal field theories which we show to have tensionless strings on their four-dimensional intersection. Moreover, we argue that the SU(2)L R-symmetry of the dCFT matches the manifest SU(2) R-symmetry of the M5-M5 intersection. We finally explore the fascinating idea of deconstructing M-theory itself. We give arguments for an equivalence of M-theory on a certain background with the Higgs branch of a four-dimensional non-supersymmetric (quiver) gauge theory: in addition to a string theoretical motivation, we find wrapped M2-branes in the mass spectrum of the quiver theory at low energies. [source] At the crossroads: feminism, psychoanalysis, politics,PSYCHOTHERAPY AND POLITICS INTERNATIONAL, Issue 1 2004Muriel Dimen Abstract Feminism, psychoanalysis, and politics have evolved together. This paper situates their interimplicated evolution in the intellectual shift from dualism to multiplicity, from binary toward pluralism. The method used is to replace dualities with triads, to move from ,either/or' to ,both/and', to bring The Third into play. Accordingly, the tale is told at the conjunction of personal, political, and theoretical discourses. Three concepts , paradox, contingency, and dialectics , limn this triple crossroads: feminism as cultural, personal, and intellectual; psychoanalysis as a clinical, theoretical, and social practice; politics as subjective, historical, and contextual. Copyright © 2004 Whurr Publishers Ltd. [source] Wellness and Impairment: Moving Beyond Noble Us and Troubled ThemCLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 1 2009Glenn E. Good Psychologists tend to view wellness and impairment in dangerous dualities. In actuality, our level of functioning varies continuously due to multiple factors. We examine factors influencing psychologists' level of functioning, and offer recommendations for individuals and the profession. In addition, we explore topics too often considered taboo in discussions of psychologist impairment, such as depression and suicide, with the hope that such discussions can help prevent future problems. In sum, wellness and impairment should not be viewed as an "Us and Them" issue, but rather as an "Us and When" issue. [source] Duality Theory and Long,Period Price SystemsMETROECONOMICA, Issue 4 2002Arrigo Opocher This paper concerns duality between long,period price systems in Sraffian models of production and the technologies of the various industries. We present a ,principle of duality between prices and technique' referred to a system of production, due to Bidard and Salvadori, and compare it with the usual textbook duality between cost and production functions, referred to firms/industries. We argue that the principle of duality for the system of production can be obtained, industry by industry, on the basis of the usual duality theory and that, in so doing, both ,dualities' are given a formulation more appropriate to firms/industries in long,period equilibrium. [source] Board Monitoring, Regulation, and Performance in the Banking Industry: Evidence from the Market for Corporate ControlCORPORATE GOVERNANCE, Issue 5 2010Jens Hagendorff ABSTRACT Manuscript Type: Empirical Research Question/Issue: The specific monitoring effect of boards of directors versus industry regulation is unclear. In this paper, we examine how the interaction between bank-level monitoring and regulatory regimes influences the announcement period returns of acquiring banks in the US and twelve European economies. Research Findings/Insights: We study three board monitoring mechanisms , independence, CEO-chair duality, and diversity , and analyze their effectiveness in preventing underperforming merger strategies under bank regulators of varying strictness. Only under strict banking regulation regimes, do board independence and diversity improve acquisition performance. In less strict regulatory environments, corporate governance is virtually irrelevant in improving the performance outcomes of merger activities. Theoretical/Academic Implications: Our results indicate a complementary role between monitoring by boards and bank regulation. This study is the first to report evidence consistent with complementarity by investigating the effectiveness (rather than the prevalence) of governance arrangements across regulatory regimes. Practitioner/Policy Implications: Our work offers insights to policymakers charged with improving the quality of decision-making at financial institutions. Attempts to improve the ability of bank boards to critically assess managerial initiatives are most likely to be successful if internal governance is accompanied by strict industry regulation. [source] Analysing Macro-Poverty Linkages of External Liberalisation: Gaps, Achievements and AlternativesDEVELOPMENT POLICY REVIEW, Issue 3 2005Bernhard G. Gunter CGE modelling has dominated analysis of the impact of external liberalisation on poverty. This article provides a structuralist critique of standard neo-classical CGE models. It highlights five sets of gaps and partial achievements in the modelling of issues affecting the poverty impact of macroeconomic policies: duality and structural rigidities; efficiency gains and quota rents; the investment and savings specification; the nature of public expenditures; and the modelling of financial fragility, risk premia and issues of credibility. It outlines a model that makes it possible to analyse more plausible stories about the impact of both current and capital account liberalisation and questions the realism of existing approaches to ex-ante poverty impact assessment. [source] Knightly Complements: The Malcontent and the Matter of WitENGLISH LITERARY RENAISSANCE, Issue 2 2010Ian Munro This essay uses John Marston's play The Malcontent to explore the social understanding and cultural practice of wit in the early modern period. Through the interactions between its various versions, The Malcontent charts the linguistic, stylistic, and cultural boundaries of early modern wit as both intrinsic class marker and promiscuous commodity. This duality of wit helps the play negotiate the complexities of its own theatrical genealogy that not only inform the larger context of wit in the period, but also inflect, in significant ways, the play's modern reception. (I.M.) [source] Language, Duality, and Bastardy in English Renaissance DramaENGLISH LITERARY RENAISSANCE, Issue 2 2004Nicholas Crawford By figuring language and thoughts as illegitimate, these locutions displace or confuse a discourse of blood lineage and social status with one that registers uneasiness about the derivation of ideas and their expression. This fantasized genealogy of bastard conceptions and their linguistic progeny signals the mind's growing alienation from the body and reveals an incipient Cartesian separation of the two. As the theater provides a spectacle of words bodied forth, it is often the drama of the early modern period that most strikingly enacts this developing duality so characteristic of modern subjectivity: the movement of language toward a realm imagined to be incorporeal. [source] Agriculture Under the Public Eye: Who Cares for WhatEUROCHOICES, Issue 2 2004Cees Veerman Summary Agriculture Under the Public Eye: Who Cares for What? The new CAP is becoming geared towards a more sustainable agriculture that takes account of the needs of future generations. Achieving sustainability, however, means meeting three challenges-, (a) profit - strengthening the viability and competitiveness of the agricultural sector; (b) planet - the ecological challenge of promoting good environmental practices; and (c) people-the social challenge to improve the living conditions and economic opportunities in rural areas. In the food chain we see responses to consumer concerns about food safety, quality and welfare issues through the development and implementation of mandatory and voluntary quality control and assurance schemes. And the consolidation and internationalisation of the food retailing and the manufacturing industry is expected to continue. An important duality has emerged. On the one side, we find a state system of regulation, on the other a system of self-regulation, largely driven by the major forces in supply chain management, the food retailers in particular. A simple and effective regulatory environment for the agri-food complex is essential if we are to achieve our competitiveness goals. One of the priorities for discussion by politicians, therefore, should be whether current and expected policy and industry developments should lead to a review of the balance between markets and government, ,who cares for what?' l'agriculture aux yeux des politiques publiques qui doit faire quoi? La nouvelle PAC est maintenant bien orientée vers une agriculture plus durable, en mesure de tenir compte des besoins des générations futures. Une véritable durabilityé suppose cependant que soient relevés trois défis: a) le profit - renforcer la viabilityé et la compétitivité du secteur agricole; b) la planète - le défiécologique de promouvoir des pratiques favorables à l'environnement; c) les gens - le défi social d'améliorer les conditions de vie et les opportunités économiques dans les zones rurales. Du côté des filières alimentaires, la réponse à trouver aux inquiétudes des consommateurs vis à vis de la qualityé sanitaire et organoleptique des produits devrait pouvoir venir de l'élaboration de contrôles de qualityé et de systèmes d'assurances, à appliquer sur la base du volontariat ou à rendre obligatoires. En même temps, il faut s'attendre à la continuation du mouvement vers l'affermissement du rôle des industries alimentaires et du commerce de détail, ainsi qu'à leur internationalisation. Un système dual vient d'émerger: d'un côté, un système de réglementations étatiques, de l'autre, une autodiscipline, pilotée par les plus solides des maillons de la filière, en particulier les grandes surfaces. Un environnement réglementaire à la fois simple et efficace est essentiel pour atteindre l'objectif de compétitivité du complexe agroalimentaire, II en résulte que, pour les pouvoirs publics, une des grandes questions à discuter est de savoir dans quelle mesure l' évolution des conditions politiques et celle du développement industriel imposent une révision de l'équilibre actuel entre les marchés et les autorités gouvernementales; en d'autres termes, qui doit faire quoi ? Landwirtschaft in der öffentlichen Meinung; Wer ist wofür zuständig? Die neue GAP wird gerade auf eine nachhaltigere Landwirtschaft hin ausgerichtet, welche die Bedürfnisse der kommenden Generationen berücksichtigt. Nachhaltigkeit kann jedoch nur erzielt werden, wenn den folgenden drei Herausforderungen Rechnung getragen wird: (a) Ökonomie , Stärkung der Leistungs- und Wettbewerbsfähigkeit des Landwirtschaftssektors; (b) Ökologie , Förderung umweltgerechter Verfahrensweisen; und (c) Soziales - Verbesserung der Lebensbedingungen und der wirtschaftlichen Lage im ländlichen Raum. Im Bereich der Nahrungsmittelkette wird den Bedenken der Verbraucher hinsichtlich der Nahrun gsmittelsicherheit, der Qualität und der Wohlfahrt durch die Entwicklung und Implementierung von obligatorischen und freiwilligen Qualitätskontrollen und Sicherheitsprogrammen Rechnung getragen. Es ist davon auszugehen, dass sich die Konsolidierung und Lnternationalisierung im Bereich des Lebensmitteleinzel-handels und der weiterverarbeitenden Industrie fortsetzen wird. Es ist eine bedeutsame Dualität entstanden. Auf der einen Seite erfolgt eine Regulierung seitens des Staates, auf der anderen Seite erfolgt eine Selbstregulierung durch die Vermarktungskette, insbesondere durch den Lebensmitteleinzelhandel. Eine sowohl einfache als auch wirksame Regulierung der Agrar- und Ernährungswirtschaft ist von grundlegender Bedeutung für das Erreichen unserer Wettbewerbsziele. Daher sollte in der Politik mit Priorität diskutiert werden, ob die gegenwärtige und zukünftige Politik und auch die industrielle Entwicklung zu einem neuen Gleichgewicht zwischen Markt und Staatseingriffen führen sollte: Wer ist wofür zuständig? [source] Resource allocation algorithms for minimum rates scheduling in MIMO-OFDM systems,EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 5 2010Johannes Georg Klotz In this paper, we consider a multiple-input-multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM) downlink scenario, where each receiving mobile station has quality of service requirements, namely minimum rate requirements. For this problem we propose three heuristic resource allocation algorithms, which have a much lower complexity than the existing optimal solution (opt). We compare and evaluate these algorithms according to sum rate performance and complexity. The first strategy is based on a heuristic sum rate maximisation algorithm using the so-called eigenvalue updates. In our second algorithm, we make use of the duality of uplink and downlink, which allows us to do the allocation in the dual uplink. Finally, our third algorithm is based on the well-known zero-forcing dirty paper coding (ZF-DPC) principles, which use the Gram--Schmidt process to orthogonalise the transmissions towards the different users. Copyright © 2010 John Wiley & Sons, Ltd. [source] Unquenched flavors in the Klebanov-Strassler theoryFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 7-9 2008Article first published online: 21 JUL 200, S. Cremonesi Abstract We present an analytic solution of type IIB supergravity plus D7-branes, describing the addition of any number of flavors to the Klebanov-Strassler background. The dual field theory and its self-similar RG flow, described by a cascade of Seiberg dualities also in the presence of flavors, are discussed. The solution indicates that the dual gauge theory enjoys a duality wall in the UV. We stress the correspondence between Seiberg duality on the field theory side, and large gauge transformations on the RR and NSNS potentials on the gravity side. This contribution is mostly based on [1]. [source] Gauge/string duality in confining theoriesFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 7 2006J.D. Edelstein Abstract This is the content of a set of lectures given at the "XIII Jorge André Swieca Summer School on Particles and Fields", Campos do Jordão, Brazil in January 2005. They intend to be a basic introduction to the topic of gauge/gravity duality in confining theories. We start by reviewing some key aspects of the low energy physics of non-Abelian gauge theories. Then, we present the basics of the AdS/CFT correspondence and its extension both to gauge theories in different spacetime dimensions with sixteen supercharges and to more realistic situations with less supersymmetry. We discuss the different options of interest: placing D,branes at singularities and wrapping D,branes in calibrated cycles of special holonomy manifolds. We finally present an outline of a number of non-perturbative phenomena in non-Abelian gauge theories as seen from supergravity. [source] Lectures on the plane-wave string/gauge theory dualityFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 2-3 2004J.C. Plefka Abstract These lectures give an introduction to the novel duality relating type IIB string theory in a maximally supersymmetric plane-wave background to ,, = 4, d = 4, U(N) super Yang-Mills theory in a particular large N and large R-charge limit due to Berenstein, Maldacena and Nastase. In the first part of these lectures the duality is derived from the AdS/CFT correspondence by taking a Penrose limit of the AdS5 × S5 geometry and studying the corresponding double-scaling limit on the gauge theory side. The resulting free plane-wave superstring is then quantized in light-cone gauge. On the gauge theory side of the correspondence the composite super Yang-Mills operators dual to string excitations are identified, and it is shown how the string spectrum can be mapped to the planar scaling dimensions of these operators. In the second part of these lectures we study the correspondence at the interacting respectively non-planar level. On the gauge theory side it is demonstrated that the large N large R-charge limit in question preserves contributions from Feynman graphs of all genera through the emergence of a new genus counting parameter , in agreement with the string genus expansion for non-zero gs. Effective quantum mechanical tools to compute higher genus contributions to the scaling dimensions of composite operators are developed and explicitly applied in a genus one computation. We then turn to the interacting string theory side and give an elementary introduction into light-cone superstring field theory in a plane-wave background and point out how the genus one prediction from gauge theory can be reproduced. Finally, we summarize the present status of the plane-wave string/gauge theory duality. [source] Strings in plane wave backgrounds,FORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 12 2003A. Pankiewicz Abstract I review aspects of string theory on plane wave backgrounds emphasising the connection to gauge theory given by the BMN correspondence. Topics covered include the Penrose limit and its role in deriving the BMN duality from AdS/CFT, light-cone string field theory in the maximally supersymmetric plane wave and extensions of the correspondence to less supersymmetric backgrounds. [source] Toric duality, Seiberg duality and Picard-Lefschetz transformationsFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 7-8 2003S. Franco Toric Duality arises as an ambiguity in computing the quiver gauge theory living on a D3-brane which probes a toric singularity. It is reviewed how, in simple cases Toric Duality is Seiberg Duality. The set of all Seiberg Dualities on a single node in the quiver forms a group which is contained in a larger group given by a set of Picard-Lefschetz transformations. This leads to elements in the group (sometimes called fractional Seiberg Duals) which are not Seiberg Duality on a single node, thus providing a new set of gauge theories which flow to the same universality class in the Infra Red. [source] Momentum changes due to quantum localizationFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 4-5 2003A.J. Short The momentum changes caused by localization are a central feature of wave-particle duality. Investigating these changes in more detail, we find that single-slit diffraction relies on a form of `interaction-free' scattering, and that an ideal which-way measurement can be made without any back-reaction on the detector. We also consider Kim and Shih's recent realization of Popper's experiment, involving diffraction of entangled particles, and offer an explanation for the results. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||