Research Publications
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Item Statistical significance of close pairs of QSOs(Nature Publishing Group, 1985-11-29) Burbidge, G.; Narlikar, J. V.; Hewitt, A.Item Contribution of quasistellar objects to the cosmic X-ray background(Indian Institute of Astrophysics, 1983-01-14) Narlikar, J. V.; Burbidge, G.Item Empirical approach to cosmology(Springer, 1981-01-23) Narlikar, J. V.; Burbidge, G.A two-component model of the universe is proposed, based on the observations of discrete extragalactic sources and the microwave background radiation. The large scale dynamics of the universe is determined by the radiation component and it leads to a characteristic size of the universe of approximately 600,000 Mpc and an age of approximately one trillion years. The second component, that of matter, occurs in discrete sources which group together in super-superclusters of characteristic size approximately 6000 Mpc and age 10 billion yr. It is suggested that the Galaxy belongs to one of these super-superclusters and that observations of discrete sources are confined to this unit. A reasonable agreement with the cosmological tests is obtained on the assumption that the geometry within a typical super-supercluster is Euclidean and that the redshifts of galaxies arise from a Doppler effect due to motions originating in a local explosion which gave birth to the super-supercluster. Further observational checks on this model are proposed.Item On the Hubble and the cosmological constant(Wiley-Blackwell, 1996-10-28) Hoyle, F.; Burbidge, G.; Narlikar, J. V.We review the observational determinations of the Hubble constant which have been made in recent years. We conclude that the most likely value of H_0 is 58 km s^-1 Mpc^-1 with uncertainties of +10 and -5. Thus the age of the standard big bang model is 11.2Gyr. The discrepancy between this value and the ages of the oldest observed stars, 13-16Gyr, appears to be real, necessitating some change in the standard model. A currently favoured procedure for coping with this widely-admitted difficulty for the theory which has been favoured by many cosmologists in recent years is a rebirth of the cosmological constant lambda. Even with this constant, the observations constrain the model very severely. There are theoretical considerations as well. The problem with this constant, as it has been seen over much of the past half-century, is that it is required to have a physical dimensionality of (length)^-2 and to have a magnitude of about 10^-56cm^-2. Theoreticians have not favoured introducing such a quantity ab initio into cosmology, but attempts to explain the genesis of lambda from particle physics have yielded results that are wide of what is required by immense factors (~10^50 to ~10^100). Using an approach from a scale-invariant theory of gravity, we show that lambda can be derived correct to a factor of ~2 within the modern Universe. This derivation does not appear to be applicable to earlier phases of the Universe, which give lambda~=H^2 rather than the relation lambda~=H^2_0 that a true cosmological constant would require.Item Quasi-steady state cosmology(Dordrecht, Reidel, 1995-03-29) Hoyle, F.; Burbidge, G.; Narlikar, J. V.Item Light nuclei in the quasi-steady state cosmological model(Springer, 1995-03-22) Hoyle, F.; Burbidge, G.; Narlikar, J. V.Item Quasi-steady state cosmology : a note on criticisms by E.L. Wright(Wiley-Blackwell, 1995-08-11) Hoyle, F.; Burbidge, G.; Narlikar, J. V.We answer criticisms made by Wright of the quasi-steady-state cosmology (QSSC). It is shown that none of his criticisms is valid, and the QSSC remains a viable cosmologies theory.Item Basic theory underlying the quasi-steady state cosmology(Royal Society Publishing, 1995-02-08) Hoyle, F.; Burbidge, G.; Narlikar, J. V.Outside cosmology, the procedure normally followed in science requires the inte- gration of hyperbolic partial differential equations subject to initial data given on a free surface, which is usually taken to be a time section of spacetime. The initial data are determined in experimental science from observation and the re- sults of the integrations are also checked by observations. Friedmann (Big Bang) cosmology suffers, however, from the fact that the observations cannot determine initial conditions. Thus in that theory the initial conditions have only the weak status of guesses. There is also some question whether the correct equations are being used, since the gravitational equations of that cosmology are not scale invariant, a situation unlike the rest of physics. Since matter exists in what is supposed to be a space of finite temporal duration its origin should be explained, working from a suitable lagrangian and action. Otherwise the origin is placed outside science. This is what is done in Big Bang cosmology. In this paper we depart from the standard procedure by first deriving grav- itational equations that are scale invariant, whence it is shown that in a scale invariant gravitational theory particles have the property that the two lengths associated with them, the Compton wavelength and gravitational radius, must be comparable, i.e. they are Planck particles. It is then shown that the theory has the scope to explain the genesis of the so-called cosmological constant, and the usually required magnitude of the cosmological constant is derived. When interactions other than gravitation are included, Planck particles are un- stable. The effect of instability on newly created Planck particles is to introduce terms into the gravitational equations additional to those of general relativity. In particular, there are negative pressure terms which act to expand the universe. The energy terms are such as to suggest that particle creation must be of an ex- plosive nature and that it must occur in the neighbourhoods of highly compacted bodies, a property which appears to provide a connection between cosmological theory and high-energy astrophysics.Item Quasi-steady state cosmology(IOP Publishing, 1995-03-14) Hoyle, F.; Burbidge, G.; Narlikar, J. V.Because of a number of unsatisfactory features of the standard hot big bang cosmology, it is argued that there is a case for exploring alternative approaches to cosmology. The approach described here called the quasi steady state cosmology (QSSC, uses a field theoretic description of matter creation within the framework of general relativity. A cosmological solutions with the universe expanding exponentially along with cycles of expansion and contraction arises from mini-creation events taking place near the event horizons of highly collapsed massive objects. The now familiar phenomena like QSOs, AGN, radio sources etc. are the manifestations of matter creation in such events. In this way cosmology is seen to be related to high energy astrophysics in a very direct way. The quasi can explain the abundances of light nuclei and the microwave background, observed large scale features of the universe like the m-z relation, the source count, the angular size-redshift relation, as well as observed distribution of the ages of galaxies.Item Quasi-steady state cosmology(International Astronomical Union, 1994-03-12) Hoyle, F.; Burbidge, G.; Narlikar, J. V.