7,632 research outputs found
Collision of spinning black holes in the close limit
In this paper we consider the collision of spinning holes using first order
perturbation theory of black holes (Teukolsky formalism). With these results
(along with ones, we published in the past) one can predict the properties of
the gravitational waves radiated from the late stage inspiral of two spinning,
equal mass black holes. Also we note that the energy radiated by the head-on
collision of two spinning holes with spins (that are equal and opposite)
aligned along the common axis is more than the case in which the spins are
perpendicular to the axis of the collision.Comment: 6 pages, 3 figures, submitted to PR
Analysis of direct CP violation in decays
We investigate the possibility of observing the direct CP violation in the
decay modes and within the Standard Model.
Including the contributions arising from the tree, annihilation, QCD as well as
electroweak penguins with both time- and space-like components, we find that
the direct CP asymmetry in is very small % but
in decay it can be as large as 4%. Approximately
charged mesons are required to experimentally observe the CP asymmetry
parameter for the later case. Since this is easily accessible with the
currently running B factories, the decay mode may be pursued
to look for CP violation.Comment: Latex, 14 page
Accurate time-domain gravitational waveforms for extreme-mass-ratio binaries
The accuracy of time-domain solutions of the inhomogeneous Teukolsky equation
is improved significantly. Comparing energy fluxes in gravitational waves with
highly accurate frequency-domain results for circular equatorial orbits in
Schwarzschild and Kerr, we find agreement to within 1% or better, which we
believe can be even further improved. We apply our method to orbits for which
frequency-domain calculations have a relative disadvantage, specifically
high-eccentricity (elliptical and parabolic) "zoom-whirl" orbits, and find the
energy fluxes, waveforms, and characteristic strain in gravitational waves.Comment: 6 pages, 9 figures, 2 tables; Changes: some errors corrected.
Comparison with Frequency-domain now done in stronger fiel
Corrosion resistant coating
A method of coating a substrate with an amorphous metal is described. A solid piece of the metal is bombarded with ions of an inert gas in the presence of a magnetic field to provide a vapor of the metal which is deposited on the substrate at a sufficiently low gas pressure so that there is formed on the substrate a thin, uniformly thick, essentially pinhole-free film of the metal
Method of producing high T(subc) superconducting NBN films
Thin films of niobium nitride with high superconducting temperature (T sub c) of 15.7 K are deposited on substrates held at room temperature (approx 90 C) by heat sink throughout the sputtering process. Films deposited at P sub Ar 12.9 + or - 0.2 mTorr exhibit higher T sub c with increasing P sub N2,I with the highest T sub c achieved at P sub n2,I= 3.7 + or - 0.2 mTorr and total sputtering pressure P sub tot = 16.6 + or - 0.4. Further increase of N2 injection starts decreasing T sub c
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