146 research outputs found

    Strings, Black Holes, and Quantum Information

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    We find multiple relations between extremal black holes in string theory and 2- and 3-qubit systems in quantum information theory. We show that the entropy of the axion-dilaton extremal black hole is related to the concurrence of a 2-qubit state, whereas the entropy of the STU black holes, BPS as well as non-BPS, is related to the 3-tangle of a 3-qubit state. We relate the 3-qubit states with the string theory states with some number of D-branes. We identify a set of "large" black holes with the maximally entangled GHZ-class of states and "small" black holes with separable, bipartite and W states. We sort out the relation between 3-qubit states, twistors, octonions, and black holes. We give a simple expression for the entropy and the area of stretched horizon of "small'' black holes in terms of a norm and 2-tangles of a 3-qubit system. Finally, we show that the most general expression for the black hole and black ring entropy in N=8 supergravity/M-theory, which is given by the famous quartic Cartan E_{7(7)} invariant, can be reduced to Cayley's hyperdeterminant describing the 3-tangle of a 3-qubit state.Comment: 31 pages, 10 figures. A version to appear in Physical Revie

    Three Charge Supertubes in Type IIB Plane Wave Backgrounds

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    We deform the supersymmetric black ring of five dimensional supergravity coupled to N-1 vector multiplets to obtain an asymptotically Goedel supersymmetric black ring. For the U(1)^3 model we lift this solution to obtain a three charge D1-D5-P supertube which asymptotes to a 1/2 supersymmetric plane wave of Type IIB supergravity. Further, we also show how one may deform the asymptotically flat three charge supertube of type IIB, in the special case of vanishing KK dipole charge, to a three charge supertube which asymptotes to the maximally supersymmetric plane wave.Comment: 1+14 pages, JHEP

    Non-supersymmetric black rings as thermally excited supertubes

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    We construct a seven-parameter family of supergravity solutions that describe non-supersymmetric black rings and black tubes with three charges, three dipoles and two angular momenta. The black rings have regular horizons and non-zero temperature. They are naturally interpreted as the supergravity descriptions of thermally excited configurations of supertubes, specifically of supertubes with two charges and one dipole, and of supertubes with three charges and two dipoles. In order to fully describe thermal excitations near supersymmetry of the black supertubes with three charges and three dipoles a more general family of black ring solutions is required.Comment: 35 pages. v2: ref added and minor typo correcte

    Functional Integration Approach to Hysteresis

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    A general formulation of scalar hysteresis is proposed. This formulation is based on two steps. First, a generating function g(x) is associated with an individual system, and a hysteresis evolution operator is defined by an appropriate envelope construction applied to g(x), inspired by the overdamped dynamics of systems evolving in multistable free energy landscapes. Second, the average hysteresis response of an ensemble of such systems is expressed as a functional integral over the space G of all admissible generating functions, under the assumption that an appropriate measure m has been introduced in G. The consequences of the formulation are analyzed in detail in the case where the measure m is generated by a continuous, Markovian stochastic process. The calculation of the hysteresis properties of the ensemble is reduced to the solution of the level-crossing problem for the stochastic process. In particular, it is shown that, when the process is translationally invariant (homogeneous), the ensuing hysteresis properties can be exactly described by the Preisach model of hysteresis, and the associated Preisach distribution is expressed in closed analytic form in terms of the drift and diffusion parameters of the Markovian process. Possible applications of the formulation are suggested, concerning the interpretation of magnetic hysteresis due to domain wall motion in quenched-in disorder, and the interpretation of critical state models of superconducting hysteresis.Comment: 36 pages, 9 figures, to be published on Phys. Rev.

    Estudio del impacto de tabús y lenguaje soez en un contexto sociocultural y análisis de su traducción en "La verdadera historia de Frank Zappa"

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    Este trabajo contiene un estudio teórico de los enfoques de traducción susceptibles de haber sido utilizados para la traducción de la obra llamada The Real Frank Zappa Book. Seguidamente se comentan los aspectos sociolingüísticos pertinentes al tratamiento de tabús y del lenguaje soez en relación a la obra en cuestión. La parte práctica consta de un análisis crítico y una serie de propuestas especialmente relacionadas con los tabús y las palabrotas, y una clasificación de los diferentes usos del lenguaje soez. En conclusión, el trabajo trata de abordar los temas comentados anteriormente siempre comparándolos con la traducción del libro La verdadera historia de Frank Zappa.Aquest treball conté un estudi teòric dels enfocaments de traducció susceptibles d'haver estat utilitzats per a la traducció de l'obra anomenada La veritable història d'en Frank Zappa. Seguidament es comenten els aspectes sociolingüístics pertinents al tractament de tabús i de les paraulotes en relació a la obra. La part pràctica consta d'una anàlisi crítica i un seguit de propostes especialment relacionades amb els tabús i les paraulotes, i una classificació dels tipus d'ús que se'n poden fer d'aquestes. En conclusió, el treball intenta comprendre les qüestions esmentades anteriorment sempre comparant-les amb la traducció del llibre La veritable historia d'en Frank Zappa.This paper contains a theoretical study about the approaches of translation that might have been used for the translation of The Real Frank Zappa Book. Some aspects of sociolinguistics related to taboo and swearing that are contrasted in parallel with The Real Frank Zappa Book are also commented. This paper contains a theoretical study about the approaches of translation that might have been used for the translation of The Real Frank Zappa Book. Some aspects of sociolinguistics related to taboo and swearing that are contrasted in parallel with The Real Frank Zappa Book are also commented. This paper contains a theoretical study about the approaches of translation that might have been used for the translation of The Real Frank Zappa Book. Some aspects of sociolinguistics related to taboo and swearing that are contrasted in parallel with The Real Frank Zappa Book are also commented

    On a class of 4D Kahler bases and AdS_5 supersymmetric Black Holes

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    We construct a class of toric Kahler manifolds, M_4, of real dimension four, a subset of which corresponds to the Kahler bases of all known 5D asymptotically AdS_5 supersymmetric black-holes. In a certain limit, these Kahler spaces take the form of cones over Sasaki spaces, which, in turn, are fibrations over toric manifolds of real dimension two. The metric on M_4 is completely determined by a single function H(x), which is the conformal factor of the two dimensional space. We study the solutions of minimal five dimensional gauged supergravity having this class of Kahler spaces as base and show that in order to generate a five dimensional solution H(x) must obey a simple sixth order differential equation. We discuss the solutions in detail, which include all known asymptotically AdS_5 black holes as well as other spacetimes with non-compact horizons. Moreover we find an infinite number of supersymmetric deformations of these spacetimes with less spatial isometries than the base space. These deformations vanish at the horizon, but become relevant asymptotically.Comment: 34 pages, 3 figures. v2: formula (8.35) and other minor typos corrected; references added; accepted for publication in JHE

    Online Applied Problem-Based Learning to Determine the Shelf Life of an on-Site Solution of Refrigerated Drug

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    A problem-based online learning (PBe-L) teaching sequence was designed for calculating the shelf life (expiration date) of an on-site solution of refrigerated drug as part of activities of a Pharmaceutical Physical Chemistry course of Pharmacy major at FES Cuautitlán UNAM in Mexico. The teacher presents students the problem, a group collaborative activity is carried out to search for information in PBL cycles. Students are then shown a virtual experiment that includes experimental results. Another group collaborative activity is carried out for the search of information, for the procedural analysis of the results. Applying knowledge and understanding of the topics of chemical kinetics, temperature effect on the rate of chemical reactions and drug degradation reactions, etc., students solve the problem. Hake's factor was determined for the conceptual gain. A Likert-type satisfaction survey was conducted and compared to the results of a group that was applied to the PBL strategy in person. At the end of the sequence students achieved recognition, comprehension and application learnings and conceptual gain was high. Allowing an integration of its cognitive framework of kinetics topics

    Quasinormal modes and hidden conformal symmetry in the Reissner-Nordstrom black hole

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    It is shown that the scalar wave equation in the near-horizon limit respects a hidden SL(2,R) invariance in the Reissner-Nordstrom (RN) black hole spacetimes. We use the SL(2,R) symmetry to determine algebraically the purely imaginary quasinormal frequencies of the RN black hole. We confirm that these are exactly quasinormal modes of scalar perturbation around the near-extremal black hole.Comment: 17 pages, 1 figure, version to appear in EPJ

    Uniqueness of M-theory PP-Wave Background with Extra Supersymmetries

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    We examine Killing spinor equations of the general eleven-dimensional pp-wave backgrounds, which contain a scalar H(x^m,x^-) in the metric and a three-form \xi(x^m,x^-) in the flux. Considering non-harmonic extra Killing spinors, we show that if the backgrounds admit at least one extra Killing spinor in addition to the standard 16 Killing spinors, they can be reduced to the form with H=A_{mn}(x^-)x^mx^n and \xi(x^-) modulo coordinate transformations. We further examine the cases in which the extra Killing spinor is characterized by a set of Cartan matrices. The super-isometry algebras of the resulting backgrounds are also derived.Comment: 25 pages, LaTeX2e, comments added, version to appear in PR
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