1,083 research outputs found

    Quasi-homogeneous black hole thermodynamics

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    Although the fundamental equations of ordinary thermodynamic systems are known to correspond to first-degree homogeneous functions, in the case of non-ordinary systems like black holes the corresponding fundamental equations are not homogeneous. We present several arguments, indicating that black holes should be described by means of quasi-homogeneous functions of degree different from one. In particular, we show that imposing the first-degree condition leads to contradictory results in thermodynamics and geometrothermodynamics of black holes. As a consequence, we show that in generalized gravity theories the coupling constants like the cosmological constant, the Born-Infeld parameter or the Gauss-Bonnet constant must be considered as thermodynamic variables

    A local view on single and coupled molecules

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    The paper focuses on a novel approach to reveal ultrafast dynamics in single molecules. The main strength of the approach is towards ultrafast processes in extended multi-chromophoric molecular assemblies. Excitonically coupled systems consisting of 2 and 3 rigidly linked perylene-diimide units in a head to tail configuration are studied. Superradiance and inhibited intramolecular decay are observed and discrete jumps in femtosecond response upon break-up of the strong coupling are revealed

    Advances in nanophotonics: ultrafast & ultrasensitive

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    In this tutorial on NanoPhotonics recent advances are highlighted with focus on near field optical methods, ultra-fast probing of single molecules and ultra-sensitive detection of individual non-fluorescent nanoparticles

    What do premiums paid for bank M&As reflect? the case of the European Union

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    We analyze the takeover premiums paid for a sample of European bank mergers between 1997 and 2007. We find that acquiring banks value profitable, high-growth, and low-risk targets. We also find that the strength of bank regulation and supervision and of deposit insurance regimes in Europe has measurable effects on takeover pricing. Stricter bank regulatory regimes and stronger deposit insurance schemes lower the takeover premiums paid by acquiring banks. This result, presumably in anticipation of higher compliance costs, is mainly driven by domestic deals. Also, we find no conclusive evidence that bidders seek to extract benefits from regulators either by paying a premium for deals in less regulated regimes or becoming too big to fail.

    Notes on the postcranial osteology of the sand lizard Liolaemus azarai (Squamata: Liolaemidae)

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    We examined skeletons of seven adult and juvenile specimens of Liolaemus azarai that were cleared and double-stained. The states of twenty three postcranial skeleton characters were described and compared with others Liolaemus species. Our findings complement the current knowledge about the osteological variation in Liolaemus and the character states may include in a data matrix to future phylogenetic studies.Fil: Gonzalez Marin, Maria Andrea. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro Nacional PatagĂłnico; ArgentinaFil: Hernando, Alejandra Beatriz. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura; Argentin

    General bounds on limited broadcast domination

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    Limited dominating broadcasts were proposed as a variant of dominating broadcasts, where the broadcast function is upper bounded by a constant k . The minimum cost of such a dominating broadcast is the k -broadcast dominating number. We present a uni ed upper bound on this parameter for any value of k in terms of both k and the order of the graph. For the speci c case of the 2-broadcast dominating number, we show that this bound is tight for graphs as large as desired. We also study the family of caterpillars, providing a smaller upper bound, which is attained by a set of such graphs with unbounded order.Preprin

    Geometrothermodynamic description of magnetic materials

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    We perform a statistical and geometrothermodynamic analysis of three different models of magnetic materials, namely, the translational free model, the spin model, and the mean-field model. First, we derive the fundamental equation for each model, which is then used as input to compute the metrics of the corresponding equilibrium spaces. Analyzing the corresponding geometrothermodynamic curvatures, we conclude that they can be used to describe thermodynamic interaction, stability conditions, and the phase transition structure of the modeled substances. In all the cases, we reproduce their well-known behavior close to the Curie temperature. Moreover, in the case of the model with spin, we found a curvature singularity which corresponds to a novel transition, where a particular response function diverges, indicating the presence of second order phase transition, according to Ehrenfest classification
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