Research Papers (JVN)
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Item Big bang and quantum cosmology(-, 1985-09-05) Narlikar, J. V.Item Case against the big bang(Elsevier Science Publishers, 1999-04-14) Narlikar, J. V.This article takes a critical look at the Hot Big Bang Cosmology (HBBC). It shows that two of its strongest lines of evidence, viz the cosmic microwave background and the abundance of light nuclei are capable of being interpreted differently, and in a physically more realistic way the HBBC is shown to have shifted its ground frequently under observational constraints, changing its parameters like Ω0, Ωb, Ωλ and q0, reinterpreting inflation, bedging options on dark matter, etc. Many of its present deductions are seen to be based on untested physics and unobservable events of the very early Universe, while its beginning in a spacetime singularity indicates its incompleteness as a physical theory. The example of the quasi steady singularity indicates its incompleteness as a physical theory. The example of the quasi-steady state cosmology (QSSC) is given to demonstrate that an alternative cosmology relying more on the ongoing astrophysical properties of the Universe and directly observable events is possible. The case is therefore made that the HBBC does not hold the ‘monopoly’ to be THE model of the Universe.Item Theories and observations in cosmology(Indian National Science Academy, 1997-12-28) Narlikar, J. V.This account is meant to be both a review and a resource article for modern cosmology. In this sense it will highlight the recent developments in the subject and point to future trends; but in addition it will indicate to the reader wishing to go deeper into the various aspects of this field, the database and sources in the form of reviews, texts and conference reports.Item Limits on a microwave background without the big bang(Pergamon, 1976-01-11) Narlikar, J. V.; Edmunds, M. G.; Wickramasinghe, N. C.The possibility of explaining the cosmic microwave back- ground in terms of thermalisation of radiation from such sources as galaxies by dust grains is explored further. Relevant calcula- tions of the optical cross-sections of graphite whiskers are given and it is shown that a smeared out dust density of ^ 10~³³ g cm~³ is required. Limits are set on the large-angle anisotropy of the background which is to be expected on the basis of this model. The relative merits of the conventional explanation and the present theory are discussed and a few discriminatory observational tests proposed. Some cosmological implications of whisker grains in the intergalactic space are examined.Item Strengths and weaknesses of the big bang cosmology(Astronomical Society of India, 1992-04-15) Narlikar, J. V.This talk reviews the achievements and shortcomings of the standard hot big bang models of the universe. The achievements lie in the predictions of the expanding universe, the abundances of light nuclei, and the microwave background. These are, however, outweighed by the shortcomings e.g. evidence for anomalous redshifts, the age problem, the low abundances of helium and the failure to find any feature in the microwave background as predicted by the theories of structure formation. It is suggested that cosmologists should keep their minds open for alternative theories also. A few such suggestion are given.Item Big bang continued(Nature Publishing Group, 1992-05-28) Narlikar, J. V.; Arp, H. C.; Burbidge, G.; et al.Item Relics of the big bang(Kluwer Academic Publishers, 1989-03-14) Narlikar, J. V.Item Did the universe originate in a big bang?(Cambridge University Press, 1989-03-14) Narlikar, J. V.