49,059 research outputs found
Nonhazardous acid etches weld samples
Nonhazardous citric acid solution used with 24 volt dc power supply etches weld samples. This etching method is limited to 300 stainless steel and a small range of other high temperature alloys
Spinor two-point functions in maximally symmetric spaces
The two-point function for spinors on maximally symmetric four-dimensional spaces is obtained in terms of intrinsic geometric objects. In the massless case, Weyl spinors in anti de Sitter space can not satisfy boundary conditions appropriate to the supersymmetric models. This is because these boundary conditions break chiral symmetry, which is proven by showing that the ldquoorder parameterrdquo for a massless Dirac spinor is nonzero. We also give a coordinate-independent formula for the bispinor introduced by Breitenlohner and Freedman [1], and establish the precise connection between our results and those of Burges, Davis, Freedman and Gibbons [2]
Waveforms for Gravitational Radiation from Cosmic String Loops
We obtain general formulae for the plus- and cross- polarized waveforms of
gravitational radiation emitted by a cosmic string loop in transverse,
traceless (synchronous, harmonic) gauge. These equations are then specialized
to the case of piecewise linear loops, and it is shown that the general
waveform for such a loop is a piecewise linear function. We give several simple
examples of the waveforms from such loops. We also discuss the relation between
the gravitational radiation by a smooth loop and by a piecewise linear
approximation to it.Comment: 16 pages, 6 figures, Revte
Operation LION - Report for period of the flight of Apollo 11
Observations by Lunar International Observers Network and astronauts of lunar phenomena during Apollo 11 fligh
Geomagnetically Trapped Radiation Produced by a High-Altitude Nuclear Explosion on July 9, 1962
Geomagnetically trapped radiation produced by a high altitude nuclear explosio
Conformal Field Theory Correlators from Classical Field Theory on Anti-de Sitter Space II. Vector and Spinor Fields
We use the AdS/CFT correspondence to calculate CFT correlation functions of
vector and spinor fields. The connection between the AdS and boundary fields is
properly treated via a Dirichlet boundary value problem.Comment: 14 pages, LaTeX2e with amsmath,amsfonts packages; v2:interactions
section corrected, reference adde
Progress on stochastic background search codes for LIGO
One of the types of signals for which the LIGO interferometric gravitational
wave detectors will search is a stochastic background of gravitational
radiation. We review the technique of searching for a background using the
optimally-filtered cross-correlation statistic, and describe the state of plans
to perform such cross-correlations between the two LIGO interferometers as well
as between LIGO and other gravitational-wave detectors, in particular the
preparation of software to perform such data analysis.Comment: 7 pages, 1 encapsulated PostScript figure, uses IOP class files,
submitted to the proceedings of the 4th Amaldi meeting (which will be
published in Classical and Quantum Gravity
Stochastic background from extra-galactic double neutron stars
We present Monte Carlo simulations of the extra galactic population of
inspiralling double neutron stars, and estimate its contribution to the
astrophysical gravitational wave background, in the frequency range of ground
based interferometers, corresponding to the last thousand seconds before the
last stable orbit when more than 96 percent of the signal is released. We show
that sources at redshift z>0.5 contribute to a truly continuous background
which may be detected by correlating third generation interferometers.Comment: 13 pages, 7 figures - proceeding of a talk given at the 11th GWDAW,
to appear in CQ
Anomalies in a waterlike model confined between plates
Using molecular dynamic simulations we study a waterlike model confined
between two fixed hydrophobic plates. The system is tested for density,
diffusion and structural anomalous behavior and compared with the bulk results.
Within the range of confining distances we had explored we observe that in the
pressure-temperature phase diagram the temperature of maximum density (TMD
line), the temperature of maximum and minimum diffusion occur at lower
temperatures when compared with the bulk values. For distances between the two
layers below a certain threshold ,, only two layers of particles are
formed, for three or more layers are formed. In the case of three
layers the central layer stays liquid while the contact layers crystallize.
This result is in agreement with simulations for atomistic models
- …