Emission Of Gravitational Radiation Research Articles

Free-electron generation of gravitational radiation

The essential features of the emission of gravitational radiation by a charged particle interacting with a given external electromagnetic field are derived from a classical model. Orders of magnitude are estimated for the radiated power. Very high energies are shown to be needed in order to generate nonzero fluxes of gravitational power.

Gravitational radiation energy loss in scattering problems and the Einstein quadrupole formula

The equations of motion necessary to compute the emission of gravitational radiation during small-angle scattering according to general relativity using a fast approximation method are presented. In addition a generalization of the Lagrange expansion method to convert Poincaré invariant equations to newtonian ones is given.

The approximation of radiative effects in relativistic gravity - Gravitational radiation reaction and energy loss in nearly Newtonian systems

An argument is presented to determine the accuracy with which a solution of Einstein's field equations of gravitation must be approximated in order to describe the dominant effects of gravitational radiation emission from weak-field systems. Several previous calculations are compared in the light of this argument, and some apparent discrepancies among them are resolved. The majority of these calculations support the 'quadrupole formulae' for gravitational radiation energy loss and radiation reaction.

On the gravitational radiation formula

For electromagnetically as well as gravitationally bound quantum mechanical many-body systems the coefficients of absorption and induced emission of gravitational radiation are calculated in the first-order approximation. The results are extended subsequently to systems with arbitrary non-Coulomb-like two-particle interaction potentials; it is shown explicitly that in all cases the perturbation of the binding potentials of the bound systems by the incident gravitational wave field itself must be taken into account.

Gravitational radiation and the ultimate speed in Rosen's bimetric theory of gravity

In Rosen's “bimetric” theory of gravity the (local) speed of gravitational radiation υ g is determined by the combined effects of cosmological boundary values and nearby concentrations of matter. It is possible for υ g to be less than the speed of light. I show here that emission of gravitational radiation prevents particles of nonzero rest mass from exceeding the speed of gravitational radiation. Observations of relativistic particles place limits on υ g and the cosmological boundary values today, and observations of synchrotron radiation from compact radio sources place limits on the cosmological boundary values in the past.

Gravitational radiation and the ultimate speed in Rosen's bimetric theory of gravity: Carlton M. Caves. W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, California 91125

Emission of gravitational radiation was shown to prevent particles of nonzero rest mass from exceeding the speed of gravitational radiation.

Free-fall sources of gravitational radiation and the failure of the quadrupole formula

view Abstract Citations (4) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Free-fall sources of gravitational radiation and the failure of the quadrupole formula Cooperstock, F. I. ; Hobill, D. W. Abstract The role of nonlinearities and structure dependence in gravitational radiation emission from gravitationally bound free-fall systems is discussed. The Bondi news function confirms the failure of the quadrupole formalism, the origin of which is delineated. A new model for analyzing the emission of gravitational energy loss from a binary system is presented. Publication: The Astrophysical Journal Pub Date: January 1980 DOI: 10.1086/183157 Bibcode: 1980ApJ...235L..55C Keywords: Free Fall; Gravitational Waves; Quadrupoles; Radiation Sources; Astronomical Models; Energy Dissipation; Nonlinear Systems; Relativity; Astrophysics full text sources ADS |

Relativistic Kepler problem. I. Behavior in the distant past of orbits with gravitational radiation damping

The method of perturbation of orbital elements is used to estimate the effect of the emission of gravitational radiation on the behavior, in the distant past, of the orbit of two weakly gravitationally interacting bodies. The perturbing acceleration due to radiation reaction is computed from time derivatives of the quadrupole moment. All such systems which were bound at finite times were necessarily unbound in the past. This result, while independent of the precise details of the radiation-reaction law, does not follow solely from energy loss due to radiation emission. A consequence of possible astrophysical significance is the possibility of the mutual capture of two bodies from scattering orbits by emission of gravitational radiation.

On the ergoregion instability

Rotating, ultra-compact stars in general relativity can have an ergo-region, in which all trajectories are dragged in the direction of the star’s rotation. The existence of the ergoregion leads to a classical instability to emission of scalar, electromagnetic and gravitational radiation from the star. In this paper we calculate eigenfrequencies (including e-folding times) for stable and unstable modes of a scalar field on a background metric which has an ergoregion. Within a W. K. B. J. approximation for modes with angular dependence exp (i mϕ ), we find that unstable modes exist for all | m | > m 0 ( m 0 depending upon the star), but that the e-folding time is asymptotically τ = τ 0 exp (2 βm ), where β is of order 1. Typically, τ 0 is several orders of magnitude longer than the age of the universe. However, the techniques evolved here should be applicable to other ‘rotational dragging’ instabilities in general relativity. Particularly useful should be the result that links the eigenfrequencies to resonances in the effective potentials governing photon motion in the metric; these potentials are rotationally ‘split’.

Gravitational Radiation Energy Loss in Scattering Problems and the Einstein Quadrupole Formula

The energy loss due to the emission of gravitational radiation during small-angle scattering according to general relativity is computed by means of a fast approximation method. The results differs by a factor of about 2.3 from the one based on the assumption that the Einstein quadrupole formula applies to energy changes in the material source.

Tidal radiation

view Abstract Citations (80) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Tidal radiation. Mashhoon, B. Abstract The general theory of tides is developed within the framework of Einstein's theory of gravitation. It is based on the concept of Fermi frame and the associated notion of tidal frame along an open curve in spacetime. Following the previous work of the author an approximate scheme for the evaluation of tidal gravitational radiation is presented which is valid for weak gravitational fields. The emission of gravitational radiation from a body in the field of a black hole is discussed, and for some cases of astrophysical interest estimates are given for the contributions of radiation due to center-of-mass motion, purely tidal deformation, and the interference between the center of mass and tidal motions. Publication: The Astrophysical Journal Pub Date: September 1977 DOI: 10.1086/155500 Bibcode: 1977ApJ...216..591M Keywords: Black Holes (Astronomy); Gravitational Effects; Relativity; Tides; Astronomical Models; Gravitational Fields; Kerr Effects; Nonrelativistic Mechanics; Stellar Models; Tensor Analysis; Astrophysics full text sources ADS |

Gravitational radiation from binary systems in alternative metric theories of gravity - Dipole radiation and the binary pulsar

The generation of gravitational radiation in several currently viable metric theories of gravitation (Brans-Dicke, Rosen, Ni, and Lightman-Lee) is analyzed, and it is shown that these theories predict the emission of dipole gravitational radiation from systems containing gravitationally bound objects. In the binary system PSR 1913 + 16, this radiation results in a secular change in the orbital period of the system with a nominal magnitude of 3 parts in 100,000 per year. The size of the effect is proportional to the reduced mass of the system, to the square of the difference in (self-gravitational energy)/(mass) between the two components of the system, and to a parameter, xi, whose value varies from theory to theory. In general relativity xi equals 0, in Rosen's (1973) theory xi equals -20/3, and in Ni's (1973) theory xi equals -400/3. The current upper limit on such a secular period change is one part in 1 million per year. It is shown that further observations of the binary system that tighten this limit and that establish the masses of the components and the identity of the companion may provide a crucial test of otherwise viable alternatives to general relativity.

Dipole gravitational radiation in Rosen's theory of gravity - Observable effects in the binary system PSR 1913+16

It is shown that Rosen's (1973) bimetric theory of gravity predicts the emission of dipole gravitational radiation from binary systems containing neutron stars, such as the binary pulsar PSR 1913+16, which causes rapid changes in orbital period. The theory also predicts sizable corrections to masses inferred from orbital data and periastron-shift data. It is demonstrated that this prediction is inconsistent with the observed upper limit on period changes unless the system consists of two neutron stars whose masses differ by less than 0.3 solar mass, or a neutron star of mass less than 0.4 solar mass and a companion which must be a rapidly rotating white dwarf or a helium main-sequence star. Because Rosen's theory is in agreement with all solar-system experiments to date, this represents a feasible test of its viability.

The tidal disruption of neutron stars by black holes in close binaries

The formation of close, doubly compact binary systems from close massive binaries is considered. Massive X-ray binaries are shown to be possible progenitors of these systems. The recent observation of the binary pulsar indicates that doubly compact binary systems may exist. Reasonable scenarios can be developed in which at least one of the compact stars, in many cases, is a black hole. In general, these objects have evolved to separations less than 10 R/sub sun/, and thus their orbits decay (within 10/sup 10/ yr) via the emission of gravitational radiation. Black-hole-neutron-star collisions may therefore be possible in these systems. A model for the tidal disruption of a neutron star by the black hole in these systems is constructed, and shows that mass ejection to infinity from 1.3 M/sub sun/ neutron stars (a reasonable value suggested by evolutionary calculations) spiraling into black holes with masses less than 8--17 M/sub sun/ is possible, this range depending upon the neutron star equation of state. For much larger black hole masses, the neutron star breakup occurs inside the Schwarzschild radius of the neutron star. A statistical estimate for the frequency of black-hole-neutron-star collisions is given, and possible implications for nucleosynthesis and antineutrino emission aremore » discussed. (AIP)« less

Ejection of massive black holes from galaxies

Gravitational recoil of a gigantic black hole (M∼108–9 M⊙) formed in the nonspherical collapse of the nuclear part of a typical galaxy can take place with an appreciable speed as a consequence of the anisotropic emission of gravitational radiation. Accretion of gaseous matter during its flight through the galaxy results in the formation of a glowing shock front. The accompanying stellar captures can lead to the formation of an accretion disk-star system about the hole. Consequently, the hole can become “luminous” enough to be observable after it emerges out of the galaxy. The phenomenon seems to have an importance in relation to the observations of quasar-galaxy association in a number of cases.

A secular relativistic change in the period of a binary pulsar

THE discovery of the first binary radio pulsar PSR1913+16 by Hulse and Taylor1 stimulated an interest in using relativistic effects to calculate more details of this system.2–4 It was shown, for example, that observations of the apsidal motion could allow the masses of the pulsar and its companion to be calculated. There are many mechanisms which could cause a secular change in the observed period of a binary pulsar (for example, mass exchange magnetic friction, electromagnetic radiation). Here we would like to discuss another possibility related to a change of orbital parameters of a pulsar in a binary system and we also estimate the effect of the emission of gravitational radiation on the period of the binary.

The interaction of a quantum mechanical oscillator with gravitational radiation

Within the framework of the linearized field equations of gravitation, the interaction operators between a quantum mechanical system and an external gravitational field are derived from the general-covariant Klein-Gordon and Dirac equation. In the case of linearly polarized plane gravitational waves the transition probabilities for absorption and induced and spontaneous emission of gravitational radiation by a quantum mechanical harmonic oscillator are calculated with the help of the time-dependent perturbation method. The results coincide with the classical ones according to the correspondence principle.

A new test of general relativity

The emission of gravitational radiation by the recently discovered binary pulsar system will cause its orbital periodP to decrease at a rate which can now be predicted to beP−1dP/dt= −(3 ± 2) × 10−9yr−1 if the only orbital perturbations are of general-relativistic origin. It is shown that other sources of period change are probably less important. The accuracy of this prediction as well as the possibility of its verification will improve greatly over the next few years. This is the first observation that can test general relativity beyond the post-Newtonian approximation.

Photoproduction of Gravitational Radiation by Pulsars

Emission of gravitational radiation via photoproduction in static electromagnetic fields can equal or exceed the quadrupole contribution for pulsars whose ellipticity ε < 10−3 and may play a role in the cooling of the star. Contrary to the quadrupole emission case, radiation can take place also when the direction of the dipole moment and the rotation axis coincide. Radiation rates are also estimated for several frequency ranges of the photon spectrum.

Ultrashort-period binaries. III - The accretion of hydrogen-rich matter onto a white dwarf of one solar mass

view Abstract Citations (37) References (18) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultrashort-period binaries. III. The accretion of hydrogen-rich matter onto a white dwarf of one solar mass. Taam, R. E. ; Faulkner, J. Abstract We have followed the thermonuclear runaways which develop when white dwarfs of 1 M0 accrete hydrogenrich material at 10-10 M0 per annum, a canonical rate of accretion which would accompany the emission of gravitational radiation in ultrashort-period binaries. The existence of such thermonuclear effects is a necessar but not sufficient criterion for gravitational radiation to play an important role in the evolution of these binaries. Subject headings: binaries - dwarf novae - gravitation - white dwarf stars Publication: The Astrophysical Journal Pub Date: June 1975 DOI: 10.1086/153619 Bibcode: 1975ApJ...198..435T Keywords: Binary Stars; Mass Transfer; Stellar Evolution; Stellar Mass; White Dwarf Stars; Astronomical Models; Gravitational Fields; Hydrogen; Novae; Astrophysics full text sources ADS | Related Materials (2) Part 1: 1971ApJ...170L..99F Part 2: 1972ApJ...175L..79F