Research Papers (JVN)

Permanent URI for this collectionhttp://localhost:4000/handle/11007/400

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Start date: 1961End date: 1979

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Now showing 1 - 10 of 93
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    Statistical analysis of the angular size flux density relation
    (IAU Symposium, 1976-03-27) Narlikar, J. V.
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    Quantum fluctuations near the classical space-time singularity
    (Springer, 1979-01-03) Narlikar, J. V.
    The method of path integration is used to study the effects of quantum fluctuations in the space-time geometry near the classical singularity of general relativity. It is shown that in certain special cases explicit Feynman propagators can be constructed which enable us to evaluate these fluctuations quantitatively. The cases discussed are (i) the gravitational col- lapse of a uniform dust ball, (ii) the Friedmann cosmologies, (iii) the axisymmetric Bianchi type I cosmological model, and (iv) the general anisotropic Bianchi type I cosmological model. In all cases discussed here the quantum uncertainty grows to infinity as the classical space-time singularity is approached. In this wider regime of quantum gravitation non- singular solutions can occur with finite probabilities.
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    On the apparent superluminal separation of radio sources components
    (Willy-Blackwell, 1979-01-13) Chitre, S. M.; Narlikar, J. V.
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    Hawking process and the cosmic microwave background in a steady state universe
    (Elsevier, 1979-06-25) Narlikar, J. V.; Rana, N. C.
    It is investigated whether a large number of primordial black holes can account for the observed microwave background in a steady state universe.The answer is shown to be negative.
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    Tachyons and cosmology
    (S.N. Bose Institute, 1978-01-20) Narlikar, J. V.
    Cosmology and high energy astrophysics provide interesting settings for the study of faster than light particles, often called tachyons. Some examples of this are given and their possible implications are discussed.
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    Role of white holes in astrophysics
    (Macmillan, 1978-01-20) Narlikar, J. V.
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    Quantum fluctuations near the classical space-time singularity
    (Springer, 1978-04-03) Narlikar, J. V.
    The method of path integration is used to study the effects of quantum fluctuations in the space-time geometry near the classical singularity of general relativity. It is shown that in certain special cases explicit Feynman propagators can be constructed which enable us to evaluate these fluctuations quantitatively. The cases discussed are (i) the gravitational col- lapse of a uniform dust ball, (ii) the Friedmann cosmologies, (iii) the axisymmetric Bianchi type I cosmological model, and (iv) the general anisotropic Bianchi type I cosmological model. In all cases discussed here the quantum uncertainty grows to infinity as the classical space-time singularity is approached. In this wider regime of quantum gravitation non- singular solutions can occur with finite probabilities.
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    Tachyons and the second law of black hole physics
    (Springer, 1978-01-27) Dhurandhar, Sanjeev; Narlikar, J. V.
    It is shown that the usual proof of the second law of black hole physics breaks down if there are tachyons present in the vicinity of a black hole. Explicit cases are discussed where a tachyon of positive energy falling into the Kerr singularity actually decreases the area of the Kerr black hole.
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    Inertia and cosmology in Einstein's relativity
    (Johnson Reprint Corporation, 1979-01-02) Narlikar, J. V.
    Nature does not begin with elements, as we are obliged to begin with them. It is certainly fortunate for us, that we can, from time to time, turn aside our eyes from the overpowering unity ot" the All, and allow them to rest on individual details. Hut we should not omit, ultimately to complete and correct our views by a thorough consideration of the things which for the time being we left out of account.
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    Applications of statistical techniques to the angular size-flux density relation for extraglactic radio sources
    (Willy-Blackwell, 1977-01-14) Narlikar, J. V.; Chitre, S. M.
    The data on the angular sizes (theta) and flux densities (S) of extragalactic radio sources selected from two surveys are subjected to two independent statistical tests in order to determine whether the data warrant the conclusion that the universe is evolving. The nature of the observed scatter in the (theta, S) relation is examined, and a minimum chi-squared test is used to compare the observed (theta, S) plot with three theoretical models (one evolutionary and two nonevolutionary). A median test is then applied to compare the median angular sizes of two source samples in a narrow range of flux density. The results obtained indicate that due to the existing large scatter in the (theta, S) data, it is not possible to distinguish clearly between the evolutionary and the nonevolutionary models.