14,234 research outputs found
Binary spinning black hole Hamiltonian in canonical center-of-mass and rest-frame coordinates through higher post-Newtonian order
The recently constructed Hamiltonians for spinless binary black holes through
third post-Newtonian order and for spinning ones through formal second
post-Newtonian order, where the spins are counted of zero post-Newtonian order,
are transformed into fully canonical center-of-mass and rest-frame variables.
The mixture terms in the Hamiltonians between center-of-mass and rest-frame
variables are in accordance with the relation between the total linear momentum
and the center-of-mass velocity as demanded by global Lorentz invariance. The
various generating functions for the center-of-mass and rest-frame canonical
variables are explicitly given in terms of the single-particle canonical
variables. The no-interaction theorem does not apply because the world-line
condition of Lorentz covariant position variables is not imposed.Comment: 18 pages, no figure
Non-uniqueness of the third post-Newtonian binary point-mass dynamics
It is shown that the recently found non-uniqueness of the third
post-Newtonian binary point-mass ADM-Hamiltonian is related to the
non-uniqueness at the third post-Newtonian approximation of the applied
ADM-coordinate conditions.Comment: LaTeX, 2 pages, submitted to Phys. Rev.
Instanton Effects in Hadron Spectroscopy Revisited
We use an optimised clover action to study spectroscopy on an instanton
ensemble reconstructed from smoothed Monte Carlo configurations. Due to the
better chirality of the clover action, the artificial configurations show a
marked difference from the free field behaviour obtained with the Wilson
action. They however still fail to reproduce the physics observed on the
smoothed configurations. The presence of freely propagating quark modes is
found to be responsible for this.Comment: 3 pages, LaTeX with 4 eps figures, LATTICE99(topology
Low Energy Dynamics in Ultradegenerate QCD Matter
We study the low energy behavior of QCD Green functions in the limit that the
baryon chemical potential is much larger than the QCD scale parameter
. We show that there is a systematic low energy expansion in
powers of , where is the energy and is the
screening scale. This expansion is valid even if the effective quark-gluon
coupling is not small. The expansion is purely perturbative in the magnetic
regime . If the external momenta and energies satisfy , planar, abelian ladder diagrams involving the full quark
propagator have to be resummed but the corresponding Dyson-Schwinger equations
are closed.Comment: 4 pages, published versio
Gluon Condensate and Non-Perturbative Quark-Photon Vertex
We evaluate the quark-photon vertex non-perturbatively taking into account
the gluon condensate at finite temperature. This vertex is related to the
previously derived effective quark propagator by a QED like Ward-Takahashi
identity. The importance of the effective vertex for the dilepton production
rate from a quark-gluon plasma is stressed.Comment: 9 pages including two figure
Phasing of gravitational waves from inspiralling eccentric binaries
We provide a method for analytically constructing high-accuracy templates for
the gravitational wave signals emitted by compact binaries moving in
inspiralling eccentric orbits. By contrast to the simpler problem of modeling
the gravitational wave signals emitted by inspiralling {\it circular} orbits,
which contain only two different time scales, namely those associated with the
orbital motion and the radiation reaction, the case of {\it inspiralling
eccentric} orbits involves {\it three different time scales}: orbital period,
periastron precession and radiation-reaction time scales. By using an improved
`method of variation of constants', we show how to combine these three time
scales, without making the usual approximation of treating the radiative time
scale as an adiabatic process. We explicitly implement our method at the 2.5PN
post-Newtonian accuracy. Our final results can be viewed as computing new
`post-adiabatic' short period contributions to the orbital phasing, or
equivalently, new short-period contributions to the gravitational wave
polarizations, , that should be explicitly added to the
`post-Newtonian' expansion for , if one treats radiative effects
on the orbital phasing of the latter in the usual adiabatic approximation. Our
results should be of importance both for the LIGO/VIRGO/GEO network of ground
based interferometric gravitational wave detectors (especially if Kozai
oscillations turn out to be significant in globular cluster triplets), and for
the future space-based interferometer LISA.Comment: 49 pages, 6 figures, high quality figures upon reques
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