14,004 research outputs found

    Binary spinning black hole Hamiltonian in canonical center-of-mass and rest-frame coordinates through higher post-Newtonian order

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    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

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    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

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    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

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    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 ΛQCD\Lambda_QCD. We show that there is a systematic low energy expansion in powers of (ω/m)1/3(\omega/m)^{1/3}, where ω\omega is the energy and mm is the screening scale. This expansion is valid even if the effective quark-gluon coupling gg is not small. The expansion is purely perturbative in the magnetic regime kk0|\vec{k}| \gg k_0. If the external momenta and energies satisfy k0kk_0 \sim |\vec{k}|, 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

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    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

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    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, h+,×h_{+,\times}, that should be explicitly added to the `post-Newtonian' expansion for h+,×h_{+,\times}, 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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