Browsing by Author "Burbidge, G."

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Associations between quasi-stellar objects and galaxies
(American Astronomical Society, 1990-11-12) Burbidge, G.; Hewitt, A.; Narlikar, J. V.; et al.
Astrophysical deductions from the quasi-steady state cosmology
(Wiley-Blackwell, 1993-11-24) Hoyle, F.; Burbidge, G.; Narlikar, J. V.
The numerical consequences of the theory developed in two previous papers are examined in more detail. In particular, it is shown that the radio source count data can be explained to high accuracy, including the steeper-than-Euclidean slope of the count distribution at its high-flux end. By specifying the parameters of the theory, we obtain reasonable values for the Hubble constant and the ages of the globular clusters, a maximum redshift for any object observed from the present oscillatory cycle of the Universe, a minimum average density of ˜2 × 10¯²7 g cm¯³ for clusters of galaxies, and a temperature close to 2.7 K for the microwave background. The theory predicts a near-blackbody spectrum for the microwave background, and also explains the observed anisotropy.
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.
Big bang continued
(Nature Publishing Group, 1992-05-28) Narlikar, J. V.; Arp, H. C.; Burbidge, G.; et al.
Contribution of quasistellar objects to the cosmic X-ray background
(Indian Institute of Astrophysics, 1983-01-14) Narlikar, J. V.; Burbidge, G.
Cosmology and cosmogony in a cyclic universe
(Indian Academy of Sciences, 2007-04-26) Narlikar, J. V.; Burbidge, G.; Vishwakarma, R. G.
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 & J. V. Narlikar forty years ago. It is shown that the creation processes which take 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, He³ and He⁴). 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 – the understanding of the origin of the intrinsic redshifts, and the periodicities in the redshift distribution of the QSOs.
Counting of radio sources: is evolution necessary?
(American Astronomical Society, 1988-01-12) Dasgupta, P.; Narlikar, J. V.; Burbidge, G.
This paper suggests a new and clear-cut way of deciding whether evolutionary effects are necessary to interpret the observed radio-source counts. To this end, a method is outlined for constructing the parent radio luminosity function from a complete sample of radio sources whose redshifts are all known. It is argued that if such a luminosity function can be constructed without evolutionary parameters, then evolutionary effects are not required. The method is illustrated by its applications to two well-known samples of radio sources. It is further shown that the non-evolving luminosity function satisfies the constraint of sky brightness and is consistent with the observed redshift-flux-density plot. Thus it appears from these investigations that evolution is not required either in luminosity or in number density.
Critical reactions to the hot big bang interpretation
(Cambridge University Press, 2009-09-14) Burbidge, G.
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.
Extragalactic universe: an alternative view
(Nature Publishing Group, 1990-08-30) Narlikar, J. V.; Arp, H. C.; Burbidge, G.; et al.
We discuss evidence to show that the generally accepted view of the Big Bang model for the origin of the Universe is unsatisfactory. We suggest an alternative model that satisfies the constraints better.
Further astrophysical quantities expected in a quasi steady state universe
(EDP Sciences, 1994-02-06) Hoyle, F.; Burbidge, G.; Narlikar, J. V.
In two previous papers we have described a new cosmological model which we have called the quasi-steady state cosmological model (QSSC) (Hoyle et al. 1993, 1994). In this theory matter is created only in strong gravitational fields associated with dense aggregates of matter. In this paper and in Hoyle et al. (1994) we are attempting to show that many aspects of the observable universe are explicable using this theory so that it is a reasonable alternative to the classical Big-Bang model which has been so widely accepted. We first review briefly the theory of the creation process and show how we arrived at the quasi-oscillatory model. In later sections we show how two of the three parameters of the theory P, and Q, are related to two observed quantities. Q is related to the value of the Hubble constant H0 at the present epoch, and the counts of radio sources enable us to determine P/Q and hence P. We find that Q = 40 40⁹ years and P = 8 10¹¹ years. We then calculate numerical values for the mass density in the universe and the rate of creation. Finally, we discuss the properties of galaxies including faint galaxies, creation events in individual galaxies, and the mass-to-light ratios in galaxies and clusters. The results here are particularly interesting since in this model stars can be much older than H₀¯¹. This means that much of the mass in galaxies will naturally be baryonic and will consist of evolved stars. Thus very large mass-to-light ratios are expected in galaxies and in clusters. We conclude by summarizing the results obtained in all three papers. More work is required, particularly on the cosmogonical aspects of the theory, but a very attractive aspect of it is that the creation process in the centers of galaxies leads to a comparatively simple way of understanding explosive phenomena.
Interpretations of the accelerating universe
(Astronomical Society of the Pacific, 2002-10-26) Narlikar, J. V.; Vishwakarma, R. G.; Burbidge, G.
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.
Light nuclei in the quasi-steady state cosmological model
(Springer, 1995-03-22) Hoyle, F.; Burbidge, G.; Narlikar, J. V.
Log N-log S curve for 3CR radio galaxies and the problem of identifying faint radio galaxies
(American Astronomical Society, 1976-04-15) Burbidge, G.; Narlikar, J. V.
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.
Quasi-steady state cosmological model with creation of matter
(American Astronomical Society, 1993-06-20) Hoyle, F.; Burbidge, G.; Narlikar, J. V.
Quasi-steady state cosmology
(International Astronomical Union, 1994-03-12) Hoyle, F.; Burbidge, G.; Narlikar, J. V.
Quasi-steady state cosmology
(Dordrecht, Reidel, 1995-03-29) Hoyle, F.; Burbidge, G.; Narlikar, J. V.
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.
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.