3,852 research outputs found
Microfield Dynamics of Black Holes
The microcanonical treatment of black holes as opposed to the canonical
formulation is reviewed and some major differences are displayed. In particular
the decay rates are compared in the two different pictures.Comment: 22 pages, 4 figures, Revtex, Minor change in forma
Theoretical survey of tidal-charged black holes at the LHC
We analyse a family of brane-world black holes which solve the effective
four-dimensional Einstein equations for a wide range of parameters related to
the unknown bulk/brane physics. We first constrain the parameters using known
experimental bounds and, for the allowed cases, perform a numerical analysis of
their time evolution, which includes accretion through the Earth. The study is
aimed at predicting the typical behavior one can expect if such black holes
were produced at the LHC. Most notably, we find that, under no circumstances,
would the black holes reach the (hazardous) regime of Bondi accretion.
Nonetheless, the possibility remains that black holes live long enough to
escape from the accelerator (and even from the Earth's gravitational field) and
result in missing energy from the detectors.Comment: RevTeX4, 12 pages, 4 figures, 5 tables, minor changes to match the
accepted version in JHE
The Over-Claiming Technique: Measuring Self-Enhancement Independent of Ability
Overclaiming is a concrete operationalization of self-enhancement based on respondentsâ ratings of their knowledge of various persons, events, products, and so on. Because 20% of the items are nonexistent, responses can be analyzed with signal detection formulas to index both response bias (over-claiming) and accuracy (knowledge). Study 1 demonstrated convergence of over-claiming with alternative measures of self-enhancement but independence from cognitive ability. In Studies 2â3, the validity of the overclaiming index held even when respondents were (a) warned about the foils or (b) asked to fake good. Study 3 also showed the utility of the over-claiming index for diagnosing faking. In Study 4, the over-claiming technique was applied to the debate over the adaptive value of positive illusions
On dispersion relations and the statistical mechanics of Hawking radiation
We analyze the interplay between dispersion relations for the spectrum of
Hawking quanta and the statistical mechanics of such a radiation. We first find
the general relation between the occupation number density and the energy
spectrum of Hawking quanta and then study several cases in details. We show
that both the canonical and the microcanonical picture of the evaporation lead
to the same linear dispersion relation for relatively large black holes. We
also compute the occupation number obtained by instead assuming that the
spectrum levels out (and eventually falls to zero) for very large momenta and
show that the luminosity of black holes is not appreciably affected by the
modified statistics.Comment: LaTeX, 12 pages, 6 eps figures included, final version to appear in
Class. Quantum Gravit
A lower limit for Newtonian-noise models of the Einstein Telescope
The Einstein Telescope (ET) is a proposed third-generation gravitational-wave (GW) underground observatory. It will have greatly increased sensitivity compared to current GW detectors, and it is designed to extend the observation band down to a few Hz. At these frequencies, a major limitation of the ET sensitivity is predicted to be due to gravitational fluctuations produced by the environment, most importantly by the seismic field, which give rise to the so-called Newtonian noise (NN). Accurate models of ET NN are crucial to assess the compatibility of an ET candidate site with the ET sensitivity target also considering a possible reduction in NN by noise cancellation. With NN models becoming increasingly complex as they include details of geology and topography, it is crucial to have tools to make robust assessments of their accuracy. For this purpose, we derive a lower bound on seismic NN spectra, which is weakly dependent on geology and properties of the seismic field. As a first application, we use the lower limit to compare it with NN estimates recently calculated for the Sardinia and Euregio Meuse-Rhine (EMR) candidate sites. We find the utility of the method, which shows an inconsistency with the predictions for the EMR site, which indicates that ET NN models require further improvement
The role of pre-school quality in promoting resilience in the cognitive development of young children
The study reported here investigates the role of pre-school education as a protective factor in the development of children who are at risk due to environmental and individual factors. This investigation builds upon earlier research by examining different kinds of 'quality' in early education and tests the hypothesis that pre-schools of high quality can moderate the impacts of risks upon cognitive development. Cognitive development was measured in 2857 English pre-schoolers at 36 and 58 months of age, together with 22 individual risks to children's development, and assessments were made of the quality of their pre-school provision. Multilevel Structural Equation Modelling revealed that: the global quality of pre-school can moderate the effects of familial risk (such as poverty); the relationships between staff and children can moderate the effects of child level risk (such as low birth weight); and the specific quality of curricular provision can moderate the effects of both. Policy makers need to take quality into account in their efforts to promote resilience in young 'at risk' children through early childhood services
An automated growth enclosure for metabolic labeling of Arabidopsis thaliana with 13C-carbon dioxide - an in vivo labeling system for proteomics and metabolomics research
<p>Abstract</p> <p>Background</p> <p>Labeling whole <it>Arabidopsis (Arabidopsis thaliana) </it>plants to high enrichment with <sup>13</sup>C for proteomics and metabolomics applications would facilitate experimental approaches not possible by conventional methods. Such a system would use the plant's native capacity for carbon fixation to ubiquitously incorporate <sup>13</sup>C from <sup>13</sup>CO<sub>2 </sub>gas. Because of the high cost of <sup>13</sup>CO<sub>2 </sub>it is critical that the design conserve the labeled gas.</p> <p>Results</p> <p>A fully enclosed automated plant growth enclosure has been designed and assembled where the system simultaneously monitors humidity, temperature, pressure and <sup>13</sup>CO<sub>2 </sub>concentration with continuous adjustment of humidity, pressure and <sup>13</sup>CO<sub>2 </sub>levels controlled by a computer running LabView software. The enclosure is mounted on a movable cart for mobility among growth environments. <it>Arabidopsis </it>was grown in the enclosure for up to 8 weeks and obtained on average >95 atom% enrichment for small metabolites, such as amino acids and >91 atom% for large metabolites, including proteins and peptides.</p> <p>Conclusion</p> <p>The capability of this labeling system for isotope dilution experiments was demonstrated by evaluation of amino acid turnover using GC-MS as well as protein turnover using LC-MS/MS. Because this 'open source' <it>Arabidopsis </it><sup>13</sup>C-labeling growth environment was built using readily available materials and software, it can be adapted easily to accommodate many different experimental designs.</p
Microcanonical statistics of black holes and bootstrap condition
The microcanonical statistics of the Schwarzschild black holes as well as the
Reissner-Nordstrm black holes are analyzed. In both cases we set
up the inequalities in the microcanonical density of states.
These are then used to show that the most probable configuration in the gases
of black holes is that one black hole acquires all of the mass and all of the
charge at high energy limit. Thus the black holes obey the statistical
bootstrap condition and, in contrast to the other investigation, we see that
U(1) charge does not break the bootstrap property.Comment: 16 pages. late
Density of Superfluid Helium Droplets
The classical integral cross sections of large superfluid 4He_N droplets and
the number of atoms in the droplets (N=10^3-10^4) have been measured in
molecular beam scattering experiments. These measurements are found to be in
good agreement with the cross sections predicted from density functional
calculations of the radial density distributions with a 10-90 % surface
thickness of 5.7\AA. By using a simple model for the density profile of the
droplets a thickness of about 6-8\AA is extracted directly from the data.Comment: 27 pages, REVTeX, 5 postscript figure
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