results for au:Narlikar_J in:gr-qc
Aug 23 2017 gr-qc
In light of the recent discoveries of binary black hole events by the LIGO detectors, we propose a new astrophysical source, namely, the mini creation event (MCE) as a possible source of gravitational waves (GW) to be detected by LIGO. The MCE is at the heart of the quasi steady state cosmology (QSSC) and is not expected to occur in standard cosmology. Generically, the MCE is anisotropic and we assume a Bianchi Tpye I model for its description. We compute its signature waveform and assume masses, distances analogous to the events detected by LIGO. By matched filtering the signal we find that, for a broad range of model parameters, the signal to noise ratio of the randomly oriented MCE is sufficiently high for a confident detection by advanced LIGO (aLIGO).We therefore propose the MCE as a viable astrophyical source of GW.
This paper calculates the expected gravitational wave background (GWB) in the quasi-steady state cosmology (QSSC). The principal sources of gravitational waves in the QSSC are the minicreation events (MCE). With suitable assumptions the GWB can be computed both numerically and with analytical methods. It is argued that the GWB in QSSC differs from that predicted for the standard cosmology and a future technology of detectors will be able to decide between the two predictions. We also derive a formula for the flux density of a typical extragalactic source of gravitational waves.
In this paper we discuss the properties of the quasi-steady state cosmological model (QSSC) developed in 1993 in its role as a cyclic model of the universe driven by a negative energy scalar field. We discuss the origin of such a scalar field in the primary creation process first described by F. Hoyle and J. V. Narlikar forty years ago. It is shown that the creation processes which takes place in the nuclei of galaxies are closely linked to the high energy and explosive phenomena, which are commonly observed in galaxies at all redshifts. The cyclic nature of the universe provides a natural link between the places of origin of the microwave background radiation (arising in hydrogen burning in stars), and the origin of the lightest nuclei (H, D, He$^3$ and He$^4$). It also allows us to relate the large scale cyclic properties of the universe to events taking place in the nuclei of galaxies. Observational evidence shows that ejection of matter and energy from these centers in the form of compact objects, gas and relativistic particles is responsible for the population of quasi-stellar objects (QSOs) and gamma-ray burst sources in the universe. In the later parts of the paper we briefly discuss the major unsolved problems of this integrated cosmological and cosmogonical scheme. These are the understanding of the origin of the intrinsic redshifts, and the periodicities in the redshift distribution of the QSOs.
Oct 06 2005 gr-qc
As an alternative view to the standard big bang cosmology the quasi-steady state cosmology(QSSC) argues that the universe was not created in a single great explosion; it neither had a beginning nor will it ever come to an end. The creation of new matter in the universe is a regular feature occurring through finite explosive events. Each creation event is called a mini-bang or, a mini creation event(MCE). Gravitational waves are expected to be generated due to any anisotropy present in this process of creation. Mini creation event ejecting matter in two oppositely directed jets is thus a source of gravitational waves which can in principle be detected by laser interferometric detectors. In the present work we consider the gravitational waveforms propagated by linear jets and then estimate the response of laser interferometric detectors like LIGO and LISA.
We examine the possible consistency of the quasi-steady state model with the newly discovered SNe Ia. The model assumes the existence of metallic dust ejected from the SNe explosions, which extinguishes light travelling over long distances. We find that the model shows a reasonable fit to the data, which improves if one takes account of the weak gravitational lensing effect of the SNe which have been observed on the brighter side.
We calculate the expected angular power spectrum of the temperature fluctuations in the microwave background radiation (MBR) generated in the quasi-steady state cosmology (QSSC). The paper begins with a brief description of how the background is produced and thermalized in the QSSC. We then discuss within the framework of a simple model, the likely sources of fluctuations in the background due to astrophysical and cosmological causes. Power spectrum peaks at $l \approx 6-10$, 180-220 and 600-900 are shown to be related in this cosmology respectively to curvature effects at the last minimum of the scale factor, clusters and groups of galaxies. The effect of clusters is shown to be related to their distribution in space as indicated by a toy model of structure formation in the QSSC. We derive and parameterize the angular power spectrum using six parameters related to the sources of temperature fluctuations at three characteristic scales. We are able to obtain a satisfactory fit to the observational band power estimates of MBR temperature fluctuation spectrum. Moreover, the values of `best fit' parameters are consistent with the range of expected values.
It is generally argued that the present cosmological observations support the accelerating models of the universe, as driven by the cosmological constant or `dark energy'. We argue here that an alternative model of the universe is possible which explains the current observations of the universe. We demonstrate this with a reinterpretation of the magnitude-redshift relation for Type Ia supernovae, since this was the test that gave a spurt to the current trend in favour of the cosmological constant.