arXiv subjects

S. Blinnikov

Publications and source records attributed to S. Blinnikov.

21 records · Page 2Linked to original sources

arXiv1999

Cosmic Gamma-ray Bursts. Lectures Presented at XXVII ITEP Winter School

The properties of the cosmic Gamma-ray Bursts (GRBs) are briefly summarized. A detailed bibliography is given with titles of the papers. Two fundamental theoretical problems are pointed out: the problem of the energy source, and the problem of compactness. I demonstrate some inconsistencies in the estimates of the fireball optical thickness that are widely used in the discussion of the latter problem. The possible connection of GRBs with the Dark Matter candidates is mentioned. I argue that GRBs can be produced by collapses or mergers of stars made of one probable Dark Matter candidate, namely the mirror particles. I speculate on the impact that the parameters of the neutrino oscillations might have on the observed properties of GRBs if the latter are the products of mirror star deaths.

astro-ph↗

arXiv1999

Gamma-ray Bursts Produced by Mirror Stars

I argue that cosmic Gamma-ray Bursts (GRB) may be produced by collapses or mergers of stars made of `mirror' matter. The mirror neutrinos (which are sterile for our matter) produced at these events can oscillate into ordinary neutrinos. The annihilations or decays of the latter create an electron-positron plasma and subsequent relativistic fireball with a very low baryon load needed for GRBs. The concept of mirror matter is able to explain several key problems of modern astrophysics: neutrino anomalies, the missing mass, MACHO microlensing events and GRBs. Thus this concept becomes very appealing and should be considered quite seriously and attentively.

astro-ph↗

arXiv1997

Expansions for nearly Gaussian distributions

Various types of expansions in series of Chebyshev-Hermite polynomials currently used in astrophysics for weakly non-normal distributions are compared, namely the Gram-Charlier, Gauss-Hermite and Edgeworth expansions. It is shown that the Gram-Charlier series is most suspect because of its poor convergence properties. The Gauss-Hermite expansion is better but it has no intrinsic measure of accuracy. The best results are achieved with the asymptotic Edgeworth expansion. We draw attention to the form of this expansion found by Petrov for arbitrary order of the asymptotic parameter and present a simple algorithm realizing Petrov's prescription for the Edgeworth expansion. The results are illustrated by examples similar to the problems arising when fitting spectral line profiles of galaxies, supernovae, or other stars, and for the case of approximating the probability distribution of peculiar velocities in the cosmic string model of structure formation.

astro-ph↗