Self interaction of spins in binary systems

Beyond point mass effects various contributions add to the radiative evolution of compact binaries. We present all the terms up to the second post-Newtonian order contributing to the rate of increase of gravitational wave frequency and the number of gravitational wave cycles left until the final coalescence for binary systems with spin, mass quadrupole and magnetic dipole moments, moving on circular orbit. We evaluate these contributions for some famous or typical compact binaries and show that the terms representing the self interaction of individual spins, given for the first time here, are commensurable with the proper spin-spin contributions for the recently discovered double pulsar J0737-3039.Comment: 6 pages, Proceedings of the Albert Einstein Century International Conference, Paris, France, 18-22 July, 200

Gravitációs hullámforma jóslatok = Gravitational wave templates

Körpályán keringő kettősök esetén megadtuk a gravitációs hullám frekvenciájának fejlődését a spin, kvadrupól és mágneses dipól momentumok figyelembe vételével. A kettős rendszerek excentrikus mozgását a Lense-Thirring közelítésben vizsgáltam. Meghatároztam a kialakuló gravitációs hullám polarizációs állapotait. A kettősök leírását kiterjesztettem arra az esetre, amikor a két test tömege összemérhető és egyikük forgása elhanyagolható, valamint az általános, összemérhető tömegű és forgású esetre. Meghatároztam a rendszert leíró dinamikai mennyiségek és a spinek polárszögeinek változását. Megadtam a kialakuló gravitációs hullám polarizációs állapotait a sugárzási tér magasabb momentumainak figyelembe vételével. Ezek az eredmények a kettős rendszer excentrikus mozgásának és sugárzásának teljes, spinben lineáris leírását teszik lehetővé. Sík, pordominált Friedman-Robertson-Walker (FRW) univerzumot vizsgáltunk kozmológiai állandó jelenlétében. Megadtuk a metrika skalár perturbációinak analitikus alakját, valamint a késői ISW teljesítményspektrumát. A Sachs-Wolfe-effektus alapján megadtuk a vektor perturbációk kozmikus mikrohullámú háttérsugárzáshoz való hozzájárulását, valamint megbecsültük a rotációs tenzorhoz tartozó szögsebesség értékét. A sűrűségfluktuációk jelenléte a pordominált, homogén és izotróp FRW univerzum perturbációit eredményezi. Ebben a perturbált FRW modellben megadtuk a skálafaktornak a sűrűségperturbációk okozta, gyorsulást leíró járulékát. | We have calculated the frequency evolution of gravitational waves for binaries on circular orbits with the inclusion of spin, quadrupole and magnetic dipole moments. The eccentric motion of the binary was analyzed in the Lense-Thirring approximation and polarization states were calculated. The description of the motion was extended to binaries with comparable masses and one spinning component, and with comparable masses and spins. The dynamical quantities and spin evolution was given. The polarization states were obtained with the inclusion of higher multipole moments. These results enable the complete description of eccentric motion and radiation of binary systems considering linear spin effects. We have analyzed flat, dust dominated Friedman-Robertson-Walker (FRW) universes with cosmological constant. The analytic form of scalar perturbations and the power spectrum of the late ISW effect were given. With the use of the Sachs-Wolfe effect we have calculated the contribution of vector perturbations to the cosmic microwave background radiation and estimated the magnitude of rotations corresponding to the rotation tensor. The presence of density fluctuations results the perturbations of a homogeneous, isotropic, dust dominated FRW universe. In this model we have calculated the contribution to the scale factor due to density fluctuations describing accelerating expansion

Eccentric first post-Newtonian waveforms for compact binaries in frequency domain with Hansen coefficients

The inspiral and merger of supermassive black hole binary systems with high orbital eccentricity are among the promising sources of the advanced gravitational wave observatories. In this paper we derive analytic ready-to-use first post-Newtonian eccentric waveform in Fourier domain with the use of Hansen coefficients. Introducing generic perturbations of celestial mechanics we have generalized the Hansen expansion to the first post-Newtonian order which are then used to express the waveforms. Taking into account the high eccentricity of the orbit leads to the appearance of secular terms in the waveform which are eliminated with the introduction of a phase shift. The waveforms have a systematic structure and as our main result these are expressed in a tabular form.Comment: 19 pages, 3 figure

Accretion processes in magnetically and tidally perturbed Schwarzschild black holes

We study the accretion process in the region of the Preston-Poisson space-time describing a Schwarzschild black hole perturbed by asymptotically uniform magnetic field and axisymmetric tidal structures. We find that the accretion disk shrinks and the marginally stable orbit shifts towards the black hole with the perturbation. The radiation intensity of the accretion disk increases, while the radius where radiation is maximal remains unchanged. The spectrum is blue-shifted. Finally, the conversion efficiency of accreting mass into radiation is decreased by both the magnetic and the tidal perturbations.Comment: to be published in Phys. Rev. D, 13 pages, 7 figures, 1 tabl

Orbital phase in inspiralling compact binaries

We derive the rate of change of the mean motion up to the second post-Newtonian order for inspiralling compact binaries with spin, mass quadrupole and magnetic dipole moments on eccentric orbits. We give this result in terms of orbital elements. We also present the related orbital phase for circular orbits.Comment: to appear in the Proceedings of the Eleventh Marcel Grossmann Meeting 2006, World Scientific, Singapore (2007