3,005 research outputs found

    Brief survey on computational solutions for Bayesian inference

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    In this paper, we present a brief review of research work attempting to tackle the issue of tractability in Bayesian inference, including an analysis of the applicability and trade-offs of each proposed solution. In recent years, the Bayesian approach has become increasingly popular, endowing autonomous systems with the ability to deal with uncertainty and incompleteness. However, these systems are also expected to be efficient, while Bayesian inference in general is known to be an NP-hard problem, making it paramount to develop approaches dealing with this complexity in order to allow the implementation of usable Bayesian solutions. Novel computational paradigms and also major developments in massively parallel computation technologies, such as multi-core processors, GPUs and FPGAs, provide us with an inkling of the roadmap in Bayesian computation for upcoming years

    Disfunção tiróidea e amiodarona

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    Although most patients remain clinically euthyroid, some develop amiodarone-induced hyperthyroidism (HPEAI) or hypothyroidism (HPOAI). The authors present a retrospective analysis of ten patients with amiodarone-induced thyroid dysfunction. Six patients were female and mean amiodarone intake was 17.7 months. HPOIA was more common (six patients). From all the patients with HPEAI, two had type 2, one had type 1, and one had type 3 hyperthyroidism. Symptoms suggestive of thyroid dysfunction occurred in five patients, most of them with HPOAI. In HPEAI, the most frequent symptom was exacerbation of arrhythmia (three patients). Discontinuation of amiodarone and treatment with levothyroxine was chosen in 83.3% of the HPOAI cases, while thyonamide treatment with corticosteroids and without amiodarone was the option in 75% of the HPEAI cases. There were three deaths, all in patients with HPEAI. HPEAI is potentially fatal. The clinical picture may be vague, so the thyroid monitoring is mandatory

    Fermionic Wigs for AdS-Schwarzschild Black Holes

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    We provide the metric, the gravitino fields and the gauge fields to all orders in the fermionic zero modes for D=5 and D=4, N=2 gauged supergravity solutions starting from non-extremal AdS--Schwarzschild black holes. We compute the Brown-York stress--energy tensor on the boundary of AdS_5 / AdS_4 spaces and we discuss some implications of the fermionic corrections to perfect fluid interpretation of the boundary theory. The complete non-linear solution, which we denote as fermionic wig, is achieved by acting with supersymmetry transformations upon the supergravity fields and that expansion naturally truncates at some order in the fermionic zero modes.Comment: 27 pages, Latex2e, no figures, 3 ancillary file

    Thermodynamic instability of doubly spinning black objects

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    We investigate the thermodynamic stability of neutral black objects with (at least) two angular momenta. We use the quasilocal formalism to compute the grand canonical potential and show that the doubly spinning black ring is thermodynamically unstable. We consider the thermodynamic instabilities of ultra-spinning black objects and point out a subtle relation between the microcanonical and grand canonical ensembles. We also find the location of the black string/membrane phases of doubly spinning black objects.Comment: 25 pages, 7 figures v2: matches the published versio

    Cardy and Kerr

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    The Kerr/CFT correspondence employs the Cardy formula to compute the entropy of the left moving CFT states. This computation, which correctly reproduces the Bekenstein--Hawking entropy of the four-dimensional extremal Kerr black hole, is performed in a regime where the temperature is of order unity rather than in a high-temperature regime. We show that the comparison of the entropy of the extreme Kerr black hole and the entropy in the CFT can be understood within the Cardy regime by considering a D0-D6 system with the same entropic properties.Comment: 20 pages; LaTeX; JHEP format; v.2 references added, v.3 Section 4 adde

    New Near Horizon Limit in Kerr/CFT

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    The extremal Kerr black hole with the angular momentum J is conjectured to be dual to CFT with central charges c_L=c_R=12J. However, the central charge in the right sector remains to be explicitly derived so far. In order to investigate this issue, we introduce new near horizon limits of (near) extremal Kerr and five-dimensional Myers-Perry black holes. We obtain Virasoro algebras as asymptotic symmetries and calculate the central charges associated with them. One of them is equivalent to that of the previous studies, and the other is non-zero, but still the order of near extremal parameter. Redefining the algebras to take the standard form, we obtain a finite value as expected by the Kerr/CFT correspondence.Comment: 25 pages, minor changes, references adde

    Microscopic Realization of the Kerr/CFT Correspondence

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    Supersymmetric M/string compactifications to five dimensions contain BPS black string solutions with magnetic graviphoton charge P and near-horizon geometries which are quotients of AdS_3 x S^2. The holographic duals are typically known 2D CFTs with central charges c_L=c_R=6P^3 for large P. These same 5D compactifications also contain non-BPS but extreme Kerr-Newman black hole solutions with SU(2)_L spin J_L and electric graviphoton charge Q obeying Q^3 \leq J_L^2. It is shown that in the maximally charged limit Q^3 -> J_L^2, the near-horizon geometry coincides precisely with the right-moving temperature T_R=0 limit of the black string with magnetic charge P=J_L^{1/3}. The known dual of the latter is identified as the c_L=c_R=6J_L CFT predicted by the Kerr/CFT correspondence. Moreover, at linear order away from maximality, one finds a T_R \neq 0 quotient of the AdS_3 factor of the black string solution and the associated thermal CFT entropy reproduces the linearly sub-maximal Kerr-Newman entropy. Beyond linear order, for general Q^3<J_L^2, one has a finite-temperature quotient of a warped deformation of the magnetic string geometry. The corresponding dual deformation of the magnetic string CFT potentially supplies, for the general case, the c_L=c_R=6J_L CFT predicted by Kerr/CFT.Comment: 18 pages, no figure

    Hidden Conformal Symmetry of Extremal Kerr-Bolt Spacetimes

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    We show that extremal Kerr-Bolt spacetimes have a hidden conformal symmetry. In this regard, we consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt spacetimes and find in the "near region", the wave equation in extremal limit can be written in terms of the SL(2,R)SL(2,R) quadratic Casimir. Moreover, we obtain the microscopic entropy of the extremal Kerr-Bolt spacetimes also we calculate the correlation function of a near-region scalar field and find perfect agreement with the dual 2D CFT.Comment: 13 page

    Holography at an Extremal De Sitter Horizon

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    Rotating maximal black holes in four-dimensional de Sitter space, for which the outer event horizon coincides with the cosmological horizon, have an infinite near-horizon region described by the rotating Nariai metric. We show that the asymptotic symmetry group at the spacelike future boundary of the near-horizon region contains a Virasoro algebra with a real, positive central charge. This is evidence that quantum gravity in a rotating Nariai background is dual to a two-dimensional Euclidean conformal field theory. These results are related to the Kerr/CFT correspondence for extremal black holes, but have two key differences: one of the black hole event horizons has been traded for the cosmological horizon, and the near-horizon geometry is a fiber over dS_2 rather than AdS_2.Comment: 15 page

    The RN/CFT Correspondence Revisited

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    We reconsidered the quantum gravity description of the near horizon extremal Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS2_2/CFT1_1 correspondence. We found that, for pure electric case, the right moving central charge of dual 1D CFT is 6Q26 Q^2 which is different from the previous result 6Q36 Q^3 of left moving sector obtained by warped AdS3_3/CFT2_2 description. We discussed the discrepancy in these two approaches and examined novel properties of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include
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