2,385 research outputs found

    The 25 October 2010 Mentawai tsunami earthquake (M_w 7.8) and the tsunami hazard presented by shallow megathrust ruptures

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    The 25 October 2010 Mentawai, Indonesia earthquake (M_w 7.8) ruptured the shallow portion of the subduction zone seaward of the Mentawai islands, off-shore of Sumatra, generating 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands that took at least 431 lives. Analyses of teleseismic P, SH and Rayleigh waves for finite-fault source rupture characteristics indicate ∼90 s rupture duration with a low rupture velocity of ∼1.5 km/s on the 10° dipping megathrust, with total slip of 2–4 m over an ∼100 km long source region. The seismic moment-scaled energy release is 1.4 × 10^(−6), lower than 2.4 × 10^(−6) found for the 17 July 2006 Java tsunami earthquake (M_w 7.8). The Mentawai event ruptured up-dip of the slip region of the 12 September 2007 Kepulauan earthquake (M_w 7.9), and together with the 4 January 1907 (M 7.6) tsunami earthquake located seaward of Simeulue Island to the northwest along the arc, demonstrates the significant tsunami generation potential for shallow megathrust ruptures in regions up-dip of great underthrusting events in Indonesia and elsewhere

    Mesons from global Anti-de Sitter space

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    In the context of gauge/gravity duality, we study both probe D7-- and probe D5--branes in global Anti-de Sitter space. The dual field theory is N=4 theory on R x S^3 with added flavour. The branes undergo a geometrical phase transition in this geometry as function of the bare quark mass m_q in units of 1/R with R the S^3 radius. The meson spectra are obtained from fluctuations of the brane probes. First, we study them numerically for finite quark mass through the phase transition. Moreover, at zero quark mass we calculate the meson spectra analytically both in supergravity and in free field theory on R x S^3 and find that the results match: For the chiral primaries, the lowest level is given by the zero point energy or by the scaling dimension of the operator corresponding to the fluctuations, respectively. The higher levels are equidistant. Similar results apply to the descendents. Our results confirm the physical interpretation that the mesons cannot pair-produce any further when their zero-point energy exceeds their binding energy.Comment: 43 pages, 8 figures, references edited, few typos corrected, updated to match the published versio

    Holographic Flavor Transport in Arbitrary Constant Background Fields

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    We use gauge-gravity duality to compute a new transport coefficient associated with a number Nf of massive N=2 supersymmetric hypermultiplet fields propagating through an N=4 SU(Nc) super-Yang-Mills theory plasma in the limits of large Nc and large 't Hooft coupling, with Nf << Nc. We introduce a baryon number density as well as arbitrary constant electric and magnetic fields, generalizing previous calculations by including a magnetic field with a component parallel to the electric field. We can thus compute all components of the conductivity tensor associated with transport of baryon number charge, including a component never before calculated in gauge-gravity duality. We also compute the contribution that the flavor degrees of freedom make to the stress-energy tensor, which exhibits divergences associated with the rates of energy and momentum loss of the flavor degrees of freedom. We discuss two currents that are free from these divergences, one of which becomes anomalous when the magnetic field has a component parallel to the electric field and hence may be related to recent study of charge transport in the presence of anomalies.Comment: 27 page

    Проект функционального размещения нестационарных торговых объектов на территории муниципального образования "Город Томск"

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    Выпускная квалификационная работа содержит 125 с., 13 рис., 9 табл., 31 источников, 6 приложений. Ключевые слова: потребительский рынок, нестационарный торговый объект, земельный участок, земли муниципальной собственности, размещение, киоск, павильон, ярмарка, критерии, аукцион, схема размещения НТО, территориальные зоны, типовой проект. Объектом исследования является земельный участок, находящий на землях муниципальной собственности или неразграниченной государственной собственности, находящийся по адресу: Томская обл., г. Томск, р-н Октябрьский, ул. Пушкина, 56/1 ст1. Цель работы - разработка проекта функционального размещения НТО на территории муниципального образования «Город Томск». В процессе выполнения выпускной квалификационной работы проводилось изучение теоретических аспектов ноFinale qualifiziert Arbeit enthält 125 p., 13 Abb., 9 Tabellen., 31 Quellen, 6-Anwendungen. Stichwort: Verbrauchermarkt, unsicherer gewerbliche Immobilien, Grundstücke, stadteigenen Grundstück, Unterkunft, Kioske, Pavillons, faire Kriterien, Auktion, Layout NTO, territorialen Bereich, ein Modellprojekt. Das Ziel der Forschung ist ein Grundstück, auf dem Land befindet oder auf nicht-kommunalen Eigentums, Staatseigentum, an der Adresse:. Tomsk, Tomsk, Oktyabrskiy Bezirk Str. Puschkin, 56/1 CT1. Der Zweck der Arbeit - Entwicklung funktioneller Unterkunft NTO im Gebiet der Gemeinde "Stadt Tomsk". Während der Ausführung der letzten Qualifikationsarbeiten durchgeführt, die theoretischen Aspekte des Rechts zu studieren - Rechtsrahmen für die Regulierung und Platzierung NTO in Tomsk. Die Studie i

    Non-Equilibrium Field Dynamics of an Honest Holographic Superconductor

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    Most holographic models of superconducting systems neglect the effects of dynamical boundary gauge fields during the process of spontaneous symmetry-breaking. Usually a global symmetry gets broken. This yields a superfluid, which then is gauged "weakly" afterwards. In this work we build (and probe the dynamics of) a holographic model in which a local boundary symmetry is spontaneously broken instead. We compute two-point functions of dynamical non-Abelian gauge fields in the normal and in the broken phase, and find non-trivial gapless modes. Our AdS3 gravity dual realizes a p-wave superconductor in (1+1) dimensions. The ground state of this model also breaks (1+1)-dimensional parity spontaneously, while the Hamiltonian is parity-invariant. We discuss possible implications of our results for a wider class of holographic liquids.Comment: 32 pages, 12 figures; v3: string theory derivation of setup added (section 3.1), improved presentation, version accepted by JHEP; v2: paragraph added to discussion, figure added, references added, typos correcte

    Embedding massive flavor in ABJM

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    We add massive fundamental matter to the ABJM model by adding D6-branes wrapped asymptotically over RP3. We find two types of solutions at finite temperature, one that enters the black hole and one that ends before the black hole. We analyze the behavior of the free energy as a function of temperature, and find that the system exhibits a phase transition between the two types of solutions, similar to what happens in the D3-D7 system. We also analyze the meson spectrum in the model and find several massive scalar modes, again, quite like the D3-D7 system. We end with a calculation of the conductivities in the two phases.Comment: 26 pages, 6 figures; version published in JHE

    Thermodynamics of Higher Spin Black Holes in AdS3_3

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    We discuss the thermodynamics of recently constructed three-dimensional higher spin black holes in SL(N,R)\times SL(N,R) Chern-Simons theory with generalized asymptotically-anti-de Sitter boundary conditions. From a holographic perspective, these bulk theories are dual to two-dimensional CFTs with W_N symmetry algebras, and the black hole solutions are dual to thermal states with higher spin chemical potentials and charges turned on. Because the notion of horizon area is not gauge-invariant in the higher spin theory, the traditional approaches to the computation of black hole entropy must be reconsidered. One possibility, explored in the recent literature, involves demanding the existence of a partition function in the CFT, and consistency with the first law of thermodynamics. This approach is not free from ambiguities, however, and in particular different definitions of energy result in different expressions for the entropy. In the present work we show that there are natural definitions of the thermodynamically conjugate variables that follow from careful examination of the variational principle, and moreover agree with those obtained via canonical methods. Building on this intuition, we derive general expressions for the higher spin black hole entropy and free energy which are written entirely in terms of the Chern-Simons connections, and are valid for both static and rotating solutions. We compare our results to other proposals in the literature, and provide a new and efficient way to determine the generalization of the Cardy formula to a situation with higher spin charges.Comment: 30 pages, PDFLaTeX; v2: typos corrected, explicit expressions for the free energy adde

    The action for higher spin black holes in three dimensions

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    In the context of (2+1)--dimensional Chern-Simons SL(N,R)\times SL(N,R) gauge fields and spin N black holes we compute the on-shell action and show that it generates sensible and consistent thermodynamics. In particular, the Chern-Simons action solves the integrability conditions recently considered in the literature.Comment: Paper shortened and generalized. Main results unchanged. 25 pages, Latex, no figure
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