Showing papers on "Deceleration parameter published in 1987"
TL;DR: In this paper, the authors calculate the characteristics of the signal from a coalescing binary to the first post-Newtonian order, and show that at coalescence the eccentricity of the orbit, tidal effects, and magnetic interactions can be neglected.
Abstract: At present, coalescing binary systems containing neutron stars or black holes are thought to be the most likely sources of gravitational waves to be detected by long baseline interferometers being currently designed. In this essay we calculate the characteristics of the signal from a coalescing binary to the first post-Newtonian order. We show that at coalescence the eccentricity of the orbit, tidal effects, and magnetic interactions can be neglected. We also consider the effects of the expansion of the universe on the signal. We show that observations of gravitational waves from coalescing binaries by a network of detectors will provide a wealth of astrophysical information, e.g., determination of the Hubble constant, new rungs on the cosmic distance ladder, estimates of the masses of components of the binary systems, information about the mass distribution in the universe, highly accurate tests of general relativity, and constraints on neutron-star equations of state. Further development of laser interferometers may enable determination of the deceleration parameter, provide new information about evolution of the universe, and even enable observation of such effects as gravitational lensing.
93 citations
TL;DR: In this paper, the authors discuss cosmologies where the cosmological constant λ depends on time and show that for a wide class of functions with λ of the order H 3, the system of field equations leads to a stable fix-point behaviour.
77 citations
01 Jan 1987
TL;DR: In this article, it was found that the Hubble diagrams for quasars and radio galaxies are very similar, and that the evolution of giant branch stars in the radio galaxies closely matches that of the quasar nonthermal emission.
Abstract: It is found that the Hubble diagrams for quasars and giant radio galaxies are very similar. Either the evolution of giant branch stars in the galaxies closely matches the evolution of the quasar nonthermal emission or the cosmological deceleration parameter qo is close to 3.
3 citations
01 Jan 1987
TL;DR: The problem of volume test,V/Vm, in zero pressure and matter dominated Friedmann universe model is explored under various values of deceleration parameter qo and the change of V/ Vm is sensitive at small values of z.
Abstract: The problem of volume test,V/Vm,in zero pressure and matter dominated Friedmann universe model is explored under various values of deceleration parameter qo The following conclusions are drawn (i) For different values of qo, the change of V/Vm is sensitive at small values of z Since values of V/Vm are very small at small values of z, this change exerts little effect on the average values of V/Vm (ii)