Research Papers (JVN)
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Item What a student can learn from the Saha equation(American Association of Physics Teachers, 2011-06-15) Narlikar, J. V.Item quasi-steady state cosmology(Wydawnictwa Uczelniane, 2001-06-20) Narlikar, J. V.This paper begin with a discussion of the shortcomings of standard cosmology, and then outlines an alternative cosmology called Quasi-Steady State Cosmology (QSSC). The theoretical framework and observational tests of the QSSC are next described. Finally some tests which can distinguish between the standard big bang cosmology and the QSSC are briefly mentioned.Item Alternative cosmology(Korean Astronomical Society, 1996-06-18) Narlikar, J. V.Recent discussions of observational constraints on the standard hot big bang model are reviewed and it is argued that now there is room for considering alternative cosmologies. The quasi-steady state cosmology is briefly described. This model seems to explain most of the observed features of the universe, including the m-z relation, radio source count, the light nuclear abundances and the microwave background.Item Alternative to big bang cosmology(World Scientific Publishing Company, 1995-03-15) Narlikar, J. V.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(University of South Africa, 1994-01-22) 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 attempts to relate the large scale features of the universe to the basic phenomenon of creation of matter. This theory, called the quasi steady state cosmology (QSSC), begins with a field heoretic description of matter creation within the framework of general relativity. A scalar field C of zero restmass but negative energy and stresses interacts with matter at the instants of creation thereby preserving the law of conservation of the universe expanding at an overall exponential rate along with cycles of expansion and contraction with shorter time scales. It is argued that such a solution arises from mini-creation events taking place near the event horizons of highly collapsed massive objects. The now familiar phe- nomena like QSOs, AGN , radio sources, etc. are the manifestations of matter creation in such events. These events arc cophased and the oscillations occur because of feedback between the creation process and the expansion of space. In this way he cosmology is seen to be related to high energy astrophysics in a very direct way. The QSSC can explain the abundances of light nuclei and the microwave background, the observed large scale features of the universe like the m — z relation, the source count, the angular size-redshift relation, as well as the observed distribution of the ages of galaxies. This work gives a brief review of these properties of the quasi steady state cosmology.Item Quasi-steady state cosmology(International Astronomical Union, 1994-03-12) Hoyle, F.; Burbidge, G.; Narlikar, J. V.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 Saha equation and beyond(Saha Institute of Nuclear Physics, 1993-03-28) Narlikar, J. V.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.