3,438 research outputs found
PH14-8Mo stainless steel honey comb core shear strength at elevated temperatures, 1 July 1968 - 1 July 1969
PH-8Mo stainless steel honeycomb sandwich cor
Exotic Statistics for Ordinary Particles in Quantum Gravity
Objects exhibiting statistics other than the familiar Bose and Fermi ones are
natural in theories with topologically nontrivial objects including geons,
strings, and black holes. It is argued here from several viewpoints that the
statistics of ordinary particles with which we are already familiar are likely
to be modified due to quantum gravity effects. In particular, such
modifications are argued to be present in loop quantum gravity and in any
theory which represents spacetime in a fundamentally piecewise-linear fashion.
The appearance of unusual statistics may be a generic feature (such as the
deformed position-momentum uncertainty relations and the appearance of a
fundamental length scale) which are to be expected in any theory of quantum
gravity, and which could be testable.Comment: Awarded an honourable mention in the 2008 Gravity Research Foundation
Essay Competitio
An accurate equation of state for the one component plasma in the low coupling regime
An accurate equation of state of the one component plasma is obtained in the
low coupling regime . The accuracy results from a smooth
combination of the well-known hypernetted chain integral equation, Monte Carlo
simulations and asymptotic analytical expressions of the excess internal energy
. In particular, special attention has been brought to describe and take
advantage of finite size effects on Monte Carlo results to get the
thermodynamic limit of . This combined approach reproduces very accurately
the different plasma correlation regimes encountered in this range of values of
. This paper extends to low 's an earlier Monte Carlo
simulation study devoted to strongly coupled systems for ({J.-M. Caillol}, {J. Chem. Phys.} \textbf{111}, 6538 (1999)). Analytical
fits of in the range are provided with a
precision that we claim to be not smaller than . HNC equation and
exact asymptotic expressions are shown to give reliable results for
only in narrow intervals, i.e. and respectively
GRAIL, an omni-directional gravitational wave detector
A cryogenic spherical and omni-directional resonant-mass detector proposed by
the GRAIL collaboration is described.Comment: 5 pages, 4 figs., contribution to proceedings GW Data Analysis
Workshop, Paris, nov. 199
Thermal Conditions for Scalar Bosons in a Curved Space Time
The conditions that allow us to consider the vacuum expectation value of the
energy-momentum tensor as a statistical average, at some particular
temperature, are given. When the mean value of created particles is stationary,
a planckian distribution for the field modes is obtained. In the massless
approximation, the temperature dependence is as that corresponding to a
radiation dominated Friedmann-like model.Comment: 14 pages (TeX manuscript
One-Loop Supergravity Corrections to the Black Hole Entropy and Residual Supersymmetry
We study the one-loop corrections to the effective on-shell action of N=2
supergravity in the background of the Reissner-Nordstrom black hole. In the
extreme case the contributions from graviton, gravitino and photon to the
one-loop corrections to the entropy are shown to cancel. This gives the first
explicit example of the supersymmetric non-renormalization theorem for the
on-shell action (entropy) for BPS configurations which admit Killing spinors.
We display the residual supersymmetry of the perturbations of a general
supersymmetric theory in a bosonic BPS background.Comment: 13 Pages, LaTe
Interaction of Wilson loops in confining vacuum
Nonperturbative and perturbative interaction mechanisms of Wilson loops in
gluodynamics are studied within the background field formalism. The first one
operates when distance between minimal surfaces of the loops is small and may
be important for sea quark effects and strong decay processes. The second
mechanism -- perturbative interaction in nonperturbative confining background
is found to be physically dominant for all loop configurations characteristic
of scattering process. It reduces to perturbative gluon exchanges at small
distances, while at larger distances it corresponds to the t-channel exchange
of (reggeized) glueball states.
Comparison to other approaches is made and possible physical applications are
discussed.Comment: LaTeX, 25 pages, 5 EPS-figure
Spectroscopic Factors in Ca and Pb from : Fully Relativistic Analysis
We present results for spectroscopic factors of the outermost shells in
Ca and Pb, which have been derived from the comparison between
the available quasielastic () data from NIKHEF-K and the corresponding
calculated cross-sections obtained within a fully relativistic formalism. We
include exactly the effect of Coulomb distortion on the electron wave functions
and discuss its role in the extraction of the spectroscopic factors from
experiment. Without any adjustable parameter, we find spectroscopic factors of
about 70\%, consistent with theoretical predictions. We compare our results
with previous relativistic and nonrelativistic analyses of () data. In
addition to Coulomb distortion effects we discuss different choices of the
nucleon current operator and also analyze the effects due to the relativistic
treatment of the outgoing-distorted and bound nucleon wave functions.Comment: 9 pages RevTeX, 5 figures can be obtained from the author
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