4,217 research outputs found

    Instantons in Four-Fermi Term Broken SUSY with General Potential

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    It is shown how to solve the Euclidean equations of motion of a point particle in a general potential and in the presence of a four-Fermi term. The classical action in this theory depends explicitly on a set of four fermionic collective coordinates. The corrections to the classical action due to the presence of fermions are of topological nature in the sense that they depend only on the values of the fields at the boundary points τ→±∞\tau \to \pm \infty. As an application, the Sine-Gordon model with a four-Fermi term is solved explicitly and the corrections to the classical action are computed.Comment: 8 page

    Contesting Conceptual Boundaries: Byzantine Literature and Its History

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    The paper presents the problems of writing a history of Byzantine literature in the context of postmodern anxieties about canonization, authority and narrative histories of literature. An essential difficulty for such a project is the fact that Byzantine literature has been viewed as a continuation of or appendix to Ancient Greek literature, while, on the other, it has been divided into 'learned' and 'vernacular,' the latter category having been defined as Modern Greek since the middle of the nineteenth century. The paper offers two sets of criteria for establishing new concepts of periodization and taxonomy. A series of examples are indicatively adduced in order to explain the scientific and ideological impasse in which Byzantine Studies have found themselves at the end of the previous century, while delineating a proposal for a different approach to content and structure of a wider synthesis. Writing a 'new' history of Byzantine literature is an experiment in proposing a radical paradigm shift by means of which this particular literary production in Medieval Greek can be studied within the broader context of Medieval European literatures as an integrated entity rather than as a separate and peripheral phase in the histories of Ancient or Modern Greek literature

    Of Masters and Servants: Hybrid Power in Theodore Laskaris’ 'Response to Mouzalon' and in the 'Tale of Livistros and Rodamne'

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    The present paper examines two Byzantine texts from the middle of the thirteenth century, ostensibly unrelated to each other: a political essay written by a young emperor and an anonymous love romance. The analysis is conducted through the concept of hybrid power, a notion initially developed by postcolonial criticism. It is shown that in the two texts authority (that of the Byzantine emperor and that of Eros as emperor) is constructed as hybrid and thus as an impossibility, though in the case of the political essay this impossibility remains unresolved, while in the romance it is actually resolved. The pronounced similarities between the two texts on the level of political ideology (e.g. the notion of friendship between master and servant, the performance of power relations, shared key concepts) informing the hybrid form of authority and its relation to its servants is a clear indication that they belong to the same socio-cultural and intellectual environment, namely the Laskarid imperial court in Nicaea around 1250

    Closed Bosonic String Partition Function in Time Independent Exact PP-Wave Background

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    The modular invariance of the one-loop partition function of the closed bosonic string in four dimensions in the presence of certain homogeneous exact pp-wave backgrounds is studied. In the absence of an axion field the partition function is found to be modular invariant. In the presence of an axion field modular invariace is broken. This can be attributed to the light-cone gauge which breaks the symmetry in the σ\sigma-, tt-directions. Recovery of this broken modular invariance suggests the introduction of twists in the world-sheet directions. However, one needs to go beyond the light-cone gauge to introduce such twists.Comment: 17 pages, added reference

    'Interfaces' 6

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    Issue No. 6 is the second open issue of Interfaces: A Journal of Medieval European Literatures. It contains contributions by Shazia Jagot (Averroes, Islam, and Heterodoxy in the Spanish Chapel 'Triumph of St Thomas Aquinas'), Julia Verkholantsev ('Et nata ex etymo fabula:' Cosmas of Prague, the Medieval Practice of 'Etymologia,' and the Writing of History), Jan Rüdiger (Orchards of Power: The Importance of Words Well Spoken in Twelfth-Century Occitania), Andria Andreou and Panagiotis A. Agapitos (Of Masters and Servants: Hybrid Power in Theodore Laskaris’ 'Response to Mouzalon' and in the 'Tale of Livistros and Rodamne'), and Francis Ingledew (Whose Troy? Whose Rome? Whose Europe? Three Medieval Londons and the London of Derek Walcott’s 'Omeros')

    Locally Weyl invariant massless bosonic and fermionic spin-1/2 action in the (Wn(4),g)\bf (W_{n(4)},g) and (U4,g)\bf (U_{4},g) space-times

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    We search for a real bosonic and fermionic action in four dimensions which both remain invariant under local Weyl transformations in the presence of non-metricity and contortion tensor. In the presence of the non-metricity tensor the investigation is extended to Weyl (Wn,g)(W_n, g) space-time while when the torsion is encountered we are restricted to the Riemann-Cartan (U4,g)(U_4, g) space-time. Our results hold for a subgroup of the Weyl-Cartan (Y4,g)(Y_4, g) space-time and we also calculate extra contributions to the conformal gravity.Comment: 16 page

    The weakly coupled fractional one-dimensional Schr\"{o}dinger operator with index 1<α≤2\bf 1<\alpha \leq 2

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    We study fundamental properties of the fractional, one-dimensional Weyl operator P^α\hat{\mathcal{P}}^{\alpha} densely defined on the Hilbert space H=L2(R,dx)\mathcal{H}=L^2({\mathbb R},dx) and determine the asymptotic behaviour of both the free Green's function and its variation with respect to energy for bound states. In the sequel we specify the Birman-Schwinger representation for the Schr\"{o}dinger operator KαP^α−g∣V^∣K_{\alpha}\hat{\mathcal{P}}^{\alpha}-g|\hat{V}| and extract the finite-rank portion which is essential for the asymptotic expansion of the ground state. Finally, we determine necessary and sufficient conditions for there to be a bound state for small coupling constant gg.Comment: 16 pages, 1 figur

    Fast Evolutionary Adaptation for Monte Carlo Tree Search

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    This paper describes a new adaptive Monte Carlo Tree Search (MCTS) algorithm that uses evolution to rapidly optimise its performance. An evolutionary algorithm is used as a source of control parameters to modify the behaviour of each iteration (i.e. each simulation or roll-out) of the MCTS algorithm; in this paper we largely restrict this to modifying the behaviour of the random default policy, though it can also be applied to modify the tree policy

    Histories of Medieval European Literatures: New Patterns of Representation and Explanation

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    Interfaces: A Journal of Medieval European Literatures is invested in bringing together the linguistic, literary, and historical expertise to take a European approach to medieval literature. The journal aims to establish a forum both for articles which move across literatures (plural) and also, more ambitiously, to foster reflections on a more elusive, but no longer entirely absent, object, European medieval literature (singular).In line with the journal’s scope and vision to promote integrated approaches to European medieval literatures, we begin by facing head-on the multiple challenges of devising new types of narratives about medieval textual cultures. We have invited papers which take a wider regional perspective and move across medieval Europe as well as papers which bring an explicitly European perspective to more specific topics (with a tighter thematic, chronological, geographic, or linguistic focus)
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