5,012 research outputs found
A Near Horizon CFT Dual for Kerr-Newman-
We show that the near horizon regime of a Kerr-Newman- (KN) black
hole, given by its two dimensional analogue Robinson and Wilczek (2005
Phys. Rev. Lett. 95 011303), is asymptotically and dual to a one
dimensional quantum conformal field theory (CFT). The s-wave contribution of
the resulting CFT's energy-momentum-tensor together with the asymptotic
symmetries, generate a centrally extended Virasoro algebra, whose central
charge reproduces the Bekenstein-Hawking entropy via Cardy's Formula. Our
derived central charge also agrees with the near extremal Kerr/CFT
Correspondence (2009 Phys. Rev. D 80, 124008) in the appropriate limits. We
also compute the Hawking temperature of the KN black hole by coupling its
Robinson and Wilczek two dimensional analogue (RW2DA) to conformal matter.Comment: 15 pages. Major edits and revisions. Final version accepted for
publication in IJMP
Near-Extremal Black Hole Thermodynamics from AdS2/CFT1 Correspondence in The Low Energy Limit of 4D Heterotic String Theory
We compute the asymptotic symmetry group of the four dimensional
near-extremal Kerr-Sen black hole within an AdS2/CFT1 correspondence. We do
this by performing a Robinson-Wilczek two dimensional reduction and construct a
quantum theory of the remaining field content. The resulting energy momentum
tensor generates an asymptotic Virasoro algebra, to s-wave, with a calculable
central extension. This center in conjunction with the proper regularized
lowest Virasoro eigen-mode yields the near-extremal Kerr-Sen entropy via the
statistical Cardy formula. Finally we analyze quantum holomorphic fluxes of the
dual CFT giving rise to a finite Hawking temperature weighted by the central
charge of the near-extremal Kerr-Sen metric.Comment: 16 pages, references added, revised for clarity. To appear in JHE
DRASTIC—INSIGHTS:querying information in a plant gene expression database
DRASTIC––Database Resource for the Analysis of Signal Transduction In Cells (http://www.drastic.org.uk/) has been created as a first step towards a data-based approach for constructing signal transduction pathways. DRASTIC is a relational database of plant expressed sequence tags and genes up- or down-regulated in response to various pathogens, chemical exposure or other treatments such as drought, salt and low temperature. More than 17700 records have been obtained from 306 treatments affecting 73 plant species from 512 peer-reviewed publications with most emphasis being placed on data from Arabidopsis thaliana. DRASTIC has been developed by the Scottish Crop Research Institute and the Abertay University and allows rapid identification of plant genes that are up- or down-regulated by multiple treatments and those that are regulated by a very limited (or perhaps a single) treatment. The INSIGHTS (INference of cell SIGnaling HypoTheseS) suite of web-based tools allows intelligent data mining and extraction of information from the DRASTIC database. Potential response pathways can be visualized and comparisons made between gene expression patterns in response to various treatments. The knowledge gained informs plant signalling pathways and systems biology investigations
Memory, metamemory, and social cues: between conformity and resistance [forthcoming]
When presented with responses of another person, people incorporate these responses into memory reports: a finding termed memory conformity. Research on memory conformity in recognition reveals that people rely on external social cues to guide their memory responses when their own ability to respond is at chance. In this way, conforming to a reliable source boosts recognition performance but conforming to a random source does not impair it. In the present study we assessed whether people would conform indiscriminately to reliable and unreliable (random) sources when they are given the opportunity to exercise metamemory control over their responding by withholding answers in a recognition test. In Experiments 1 and 2, we found the pattern of memory conformity to reliable and unreliable sources in two variants of a free-report recognition test, yet at the same time the provision of external cues did not affect the rate of response withholding. In Experiment 3, we provided participants with initial feedback on their recognition decisions, facilitating the discrimination between the reliable and unreliable source. This led to the reduction of memory conformity to the unreliable source, and at the same time modulated metamemory decisions concerning response withholding: participants displayed metamemory conformity to the reliable source, volunteering more responses in
their memory report, and metamemory resistance to the random source, withholding more responses from the memory report. Together, the results show how metamemory decisions dissociate various types of memory conformity and that memory and metamemory decisions can be independent of each other
Inter-similarity between coupled networks
Recent studies have shown that a system composed from several randomly
interdependent networks is extremely vulnerable to random failure. However,
real interdependent networks are usually not randomly interdependent, rather a
pair of dependent nodes are coupled according to some regularity which we coin
inter-similarity. For example, we study a system composed from an
interdependent world wide port network and a world wide airport network and
show that well connected ports tend to couple with well connected airports. We
introduce two quantities for measuring the level of inter-similarity between
networks (i) Inter degree-degree correlation (IDDC) (ii) Inter-clustering
coefficient (ICC). We then show both by simulation models and by analyzing the
port-airport system that as the networks become more inter-similar the system
becomes significantly more robust to random failure.Comment: 4 pages, 3 figure
Clinical evaluation of the FloTrac/VigileoTM system and two established continuous cardiac output monitoring devices in patients undergoing cardiac surgery†‡
Background Assessment of cardiac output (CO) by the FloTrac/Vigileo™ system may offer a less invasive means of determining the CO than either the pulmonary artery catheter (PAC) or the PiCCOplus™ system. The aim of this study was to compare CO measurements made using the FloTrac/Vigileo™ system with upgraded software (FCO, Edwards Lifesciences, Irvine CA, USA), the PiCCOplus™ system (PCO, Pulsion Medical Systems, Munich, Germany) and continuous CO monitoring using a PAC (CCO; Vigilance™ monitoring, Edwards Lifesciences, Irvine CA, USA) with intermittent pulmonary artery thermodilution (ICO). The study was conducted in patients undergoing elective cardiac surgery. Methods Thirty-one patients with preserved left ventricular function were enrolled. CCO, FCO, and PCO were recorded in the perioperative period at six predefined time points after achieving stable haemodynamic conditions; ICO was determined from the mean of three bolus injections. Bland-Altman analysis was used to compare CCO, FCO, and PCO with ICO. Results Bland-Altman analysis revealed a comparable mean bias and limits of agreement for all tested continuous CO monitoring devices using ICO as reference method. Agreement for all devices decreased in the postoperative period. Conclusion The performance of the FloTrac/Vigileo™ system, the PiCCOplus™, and the Vigilance™ CCO monitoring for CO measurement were comparable when tested against intermittent thermodilution in patients undergoing elective cardiac surger
The Selberg zeta function for convex co-compact Schottky groups
We give a new upper bound on the Selberg zeta function for a convex
co-compact Schottky group acting on : in strips parallel to
the imaginary axis the zeta function is bounded by
where is the dimension of the limit set of the group. This bound is
more precise than the optimal global bound , and it gives
new bounds on the number of resonances (scattering poles) of . The proof of this result is based on the
application of holomorphic -techniques to the study of the determinants
of the Ruelle transfer operators and on the quasi-self-similarity of limit
sets. We also study this problem numerically and provide evidence that the
bound may be optimal. Our motivation comes from molecular dynamics and we
consider as the simplest model of
quantum chaotic scattering. The proof of this result is based on the
application of holomorphic -techniques to the study of the determinants of
the Ruelle transfer operators and on the quasi-self-similarity of limit sets
Assessment of New Hub-and-spoke and Point-to-point Airline Network Configurations
This paper aims to provide new measures of airline network configuration with a view to analyse effectively the complexity of modern carriers' network design. It studies network configurations in the airline sector by taking into account both spatial and temporal dimensions. The spatial dimension is measured by using both the Gini index and the Freeman index, which originate from social science research. The temporal dimension is measured by the connectivity ratio, i.e. the share of indirect connections over the total number of connections. According to these indicators, the configuration of the largest full-service carriers and the largest low-cost carriers in Europe is investigated. The results show that the temporal dimension provides a clear distinction between full-service carriers and low-cost carriers; while the spatial dimension appears useful when identifying the peculiarities within groups
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