S V Dhurandhar
Articles written in Pramana – Journal of Physics
Volume 6 Issue 6 June 1976 pp 388-398 General Relativity
Tachyon trajectories in Schwarzschild’s space-time
The motion of a tachyon in the empty Schwarzschild solution outside a mass
Volume 8 Issue 2 February 1977 pp 133-143 General Relativity
Tachyon emission from white-holes
Investigations are made about the motion of a radially outward propagating tachyon which is created in the singularity with the white-hole. The problem of confinement or escape of such a tachyon from a white-hole is discussed. It is shown that the confinement or escape of the tachyon depends on the maximum radius of the white-hole and also on a parameter
Volume 22 Issue 3-4 March 1984 pp 159-171 Relativity And Cosmology
Neutrinos in gravitational collapse: Analysis of the flux profile
S V Dhurandhar C V Vishveshwara
The flux profile of the neutrinos emitted from a collapsing spherical object, as seen by a remote observer is studied. The model of the collapsing star consists of the Friedmann dust interior matched onto the Schwarzschild exterior. It is assumed that the neutrino emission occurs from an interior shell in a very short time interval. It is found that the nature of the flux profile falls into four distinct categories depending on the progress of collapse. Interesting features such as bursts, discontinuities, decay, etc are observed when the collapse has sufficiently progressed.
Volume 27 Issue 4 October 1986 pp 485-495 General Relativity
Charged particle orbits in the field of two charges placed symmetrically near a schwarzschild black hole
V Chellathurai S V Dhurandhar N Dadhich
From the Copson and Linet solution for the electrostatic field due to a point charge near a Schwarzschild black hole, we have deduced the field due to two equal charges placed symmetrically (diametrically opposite) about the hole. It turns out that the motion of a test-charged particle is completely solvable only in the equatorial plane, because the
Volume 42 Issue 3 March 1994 pp 261-270
Losses in pendular suspensions due to centrifugal coupling
Sangita N Pitre S V Dhurandhar D G Blair Ju Li
We present an analysis of the centrifugal coupling of a simple pendulum to a dissipative support. We show that such a coupling leads to an amplitude dependent quality factor. For amplitudes which could be present in laser interferometer gravitational wave detector suspensions, this mechanism could limit the quality factor of the test mass suspension significantly to 1010 and should be considered in the design of advanced LIGO type detectors.
Volume 45 Issue 5 November 1995 pp 1- Rapid Communication
Estimation of parameters of gravitational waves from coalescing binaries
R Balasubramanian B S Sathyaprakash S V Dhurandhar
In this paper we deal with the measurement of parameters of the gravitational wave signal emitted by a coalescing binary system of compact stars. We present the results of Monte Carlo simulations carried out for initial LIGO, incorporating the first post-Newtonian corrections to the waveform. Using the parameters so determined, we estimate the direction to the source. We stress the use of the time-of-coalescence rather than the time-of-arrival of the signal to determine the direction of the source. We show that this can considerably reduce the errors in the determination of the direction of the source.
Volume 55 Issue 4 October 2000 pp 545-558
Searching for gravitational waves from rotating neutron stars
Rotating neutron stars are one of the important sources of gravitational waves (GW) for the ground based as well as space based detectors. Since the waves are emitted continuously, the source is termed as a continuous gravitational wave (CGW) source. The expected weakness of the signal requires long integration times (∼year). The data analysis problem involves tracking the phase coherently over such large integration times, which makes it the most computationally intensive problem among all GW sources envisaged. In this article, the general problem of data analysis is discussed, and more so, in the context of searching for CGW sources orbiting another companion object. The problem is important because there are several pulsars, which could be deemed to be CGW sources orbiting another companion star. Differential geometric techniques for data analysis are described and used to obtain computational costs. These results are applied to known systems to assess whether such systems are detectable with current (or near future) computing resources.
Volume 97, 2023
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