1,398 research outputs found

    Inflation

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    Inflationary cosmology is reviewed. Particular attention is given to processes of creation.Comment: Invited Review Lecture at Taup200

    Preheating and Thermalization after Inflation

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    After a short review of inlationary preheating, we discuss the development of equilibrium in the frameworks of massless λΦ4\lambda \Phi^4 model. It is shown that the process is characterised by the appearance of Kolmogorov spectra and the evolution towards thermal equilibrium follows self-similar dynamics. Simplified kinetic theory gives values for all characteristic exponents which are close to what is observed in lattice simulations. This allows estimation of the resulting reheating temperature.Comment: 10 pages, 3 figures; invited talk at the Workshop on Strong and Electroweak Matter (SEWM 2002), October 2-5, 2002, Heidelberg, German

    Cuts and penalties: comment on "The clustering of ultra-high energy cosmic rays and their sources"

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    In a series of papers we have found statistically significant correlations between arrival directions of ultra-high energy cosmic rays and BL Lacertae objects. Recently, our calculations were partly repeated by Evans, Ferrer and Sarkar with different conclusions. We demonstrate that the criticism of Evans, Ferrer and Sarkar is incorrect. We also present the details of our method.Comment: Replaced with version accepted for publication in Phys. Rev.

    Correlations and Charge Composition of UHECR without Knowledge of Galactic Magnetic Field

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    We develop a formalism which allows to study correlations of charged UHECR with potential sources without using any Galactic Magnetic Field (GMF) model. The method is free of subjective chose of parameters on which the significance of correlations depends strongly. We show that correlations of the AGASA dataset with BL Lacs (found previously after reconstruction of particle trajectories in a specific GMF) are present intrinsically and can be detected without reference to a particular model of magnetic field.Comment: To be published in the Proceedings of the 28th International Cosmic Ray Conferenc

    Sources of sub-GZK cosmic rays

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    We analyze the existing evidence that BL Lacertae objects (BL Lacs) are sources of the highest-energy cosmic rays. We argue that three independent signatures observed in the real data -- (1) improvement of correlations with corrections of trajectories for the Galactic magnetic field; (2) connection between gamma-ray and UHECR emissions; (3) non-uniform distribution of correlating rays over the sky -- are consistent with the hypothesis that a substantial fraction of cosmic rays in the energy range 40-60 EeV are protons accelerated in BL Lacs.Comment: Talk at the International Workshop on Extremely High Energy Cosmic Rays, November 5-6, 2002, RIKEN, Japa

    Quantum cosmology of the brane universe

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    We canonically quantize the dynamics of the brane universe embedded into the five-dimensional Schwarzschild-anti-deSitter bulk space-time. We show that in the brane-world settings the formulation of the quantum cosmology, including the problem of initial conditions, is conceptually more simple than in the 3+1-dimensional case. The Wheeler-deWitt equation is a finite-difference equation. It is exactly solvable in the case of a flat universe and we find the ground state of the system. The closed brane universe can be created as a result of decay of the bulk black hole.Comment: 4 pages, revte
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