Research Papers (JVN)

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Start date: 2000End date: 2009

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Now showing 1 - 10 of 57
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    Critical reactions to the hot big bang interpretation
    (Cambridge University Press, 2009-09-14) Burbidge, G.
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    Indian achievement in astronomy, astrophysics, relativity and cosmology
    (PHISPC, 2009-03-13) Narlikar, J. V.
    The chapter begins with describing the pioneering work of Meghnad Saha on stellar atmospheres, followed by the work in general relativity and cosmology in two distinct schools: N. R. Sen in Calcutta and V. V. Narlikar in Banaras. P. C. Vaidya's work (Banaras) on radiating stars is very much used today, as is B. Dart's (Calcutta) work on gravitational collapse. The Raychaudhuri equation in relativistic cosmology set the trend for future work on space-time singularities in general relativity. India has been one of the major places where alternatives (J. V. Narlikar) to the big bang cosmology have flourished. The Madras Observatory made its mark in optical observations, but post-independence India saw new facilities being created at Nainital, Kodaikanal, Kavalur, Udaipur, Gurushikhar, Han Le and Giravali. Space astronomies took off with balloons, rockets and satellites. The chapter ends with a brief critique of what have been the strengths of Indian contributions to astronomy and astrophysics, and their possible weaknesses.
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    Alternative cosmologies
    (AIP Conference Proccedings, 2009-02-02) Narlikar, J. V.
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    Janibacter hoylei sp. nov., Bacillus isronensis sp. nov. and Bacillus aryabhattai sp. nov., isolated from cryotubes used for collecting air from the upper atmosphere
    (Society for General Microbiology, 2009-05-15) Narlikar, J. V.; Shivaji, S.; Chaturvedi, Preeti; et al.
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    Stratosphere microbes might hold clues to life on earth
    (Nature Publishing Group, 2009-03-25) Narlikar, J. V.
    On April 20, 2005, a 26.7 million cubic feet balloon carrying a 459 kg scientific payload with 38 kg of liquid neon was flown from the National Balloon Facility in Hyderabad operated by the Tata Institute of Fundamental Research (TIFR). The payload collected air samples from different heights ranging from 20 km to 41 km. After this operation, the payload was parachuted down and was safely retrieved. The collected samples were divided into two lots and independently analysed by the Centre for Cellular and Molecular Biology (CCMB), Hyderabad and the National Centre for Cell Science (NCCS), Pune. Both labs reported finding live microorganisms¹. Such findings have enormous implications for the budding field of astrobiology besides providing important inputs into the question of how life started on our planet.
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    Cosmological redshift
    (Indian Association of Physics Teachers, 2008-10-29) Narlikar, J. V.
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    Why can’t cosmology be more open?
    (Nature Publishing Group, 2008-01-16) Narlikar, J. V.
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    TWAN: A way of networking third-world astronomers
    (Cambridge University Press, 2007-06-30) Narlikar, J. V.
    This talk describes a proposal to set up a series of international institutions in different parts of the world to serve as nodes in a network that links astronomers from the developing nations worldwide. This network, along with its nodes is visualized as an economic way of upgrading the facilities for teaching, research and development of astronomy in the Third World countries. By way of illustration, the modus-operandi of the Inter-University Centre for Astronomy and Astrophysics in Pune, India is described. A network of this kind is suggested as a cost-efficient way of sharing limited resources.
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    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.
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    Modeling repulsive gravity with creation
    (Indian Academy of Sciences, 2007-01-18) Vishwakarma, R. G.; Narlikar, J. V.
    There is a growing interest among cosmologists for theories with negative energy scalar fields and creation, in order to model a repulsive gravity. The classical steady state cosmology proposed by Bondi, Gold & Hoyle in 1948, was the first such theory which used a negative kinetic energy creation field to invoke creation of matter. We emphasize that creation plays a very crucial role in cosmology and provides a natural explanation to the various explosive phenomena occurring in local (z < 0.1) and extra galactic universe.We exemplify this point of view by considering the resurrected version of this theory – the quasi-steady state theory, which tries to relate creation events directly to the large scale dynamics of the universe and supplies more natural explanations of the observed phenomena. Although the theory predicts a decelerating universe at the present era, it explains successfully the recent SNe Ia observations (which require an accelerating universe in the standard cosmology), as we show in this paper by performing a Bayesian analysis of the data.