Cosmological effects on the observed flux and fluence distributions of gamma-ray bursts

Several claims have been put forward that an essential fraction of long-duration BATSE gamma-ray bursts should lie at redshifts larger than 5. This point-of-view follows from the natural assumption that fainter objects should, on average, lie at larger redshifts. However, redshifts larger than 5 are rare for bursts observed by Swift. The purpose of this article is to show that the most distant bursts in general need not be the faintest ones. We derive the cosmological relationships between the observed and emitted quantities, and arrive at a prediction that is tested on the ensembles of BATSE, Swift and Fermi bursts. This analysis is independent on the assumed cosmology, on the observational biases, as well as on any gamma-ray burst model. We arrive to the conclusion that apparently fainter bursts need not, in general, lie at large redshifts. Such a behaviour is possible, when the luminosities (or emitted energies) in a sample of bursts increase more than the dimming of the observed values with redshift. In such a case dP(z)/dz > 0 can hold, where P(z) is either the peak-flux or the fluence. This also means that the hundreds of faint, long-duration BATSE bursts need not lie at high redshifts, and that the observed redshift distribution of long Swift bursts might actually represent the actual distribution.Comment: 2 pages, 1 figure; Death of Massive Stars: Supernovae and Gamma-Ray Bursts, Proceedings IAU Symposium No. 27

The Socioeconomic Background of the Divergence of Belarusian and Ukrainian Political Systems

The aim of this paper is to analyze the political, social and economic background of the divergence of Belarusian and Ukrainian transitions. We focus on Belarus in order to find explanation for questions such as why could Lukashenko remain the authoritarian leader of Belarus, while in Ukraine the position of the political elite had proved less stable and collapsed in 2004. On the theoretical framework of elite-sociology, we seek to determine whether the internal factors (as macroeconomic conditions, standard of living, the oppressive nature of the political system and the structure of the political elite) play a significant role in the operation of the domino effect. This article emphasises the determining role of immanent internal factors, thus the political stability in Belarus can be explained by the role of the suppressing political regime, the hindrance of democratic rights and the relatively good living conditions that followed the transformational recession. Whilst in Ukraine, the markedly different circumstances brought forth the success of the Orange Revolution

h-Polynomials of Reduction Trees

Reduction trees are a way of encoding a substitution procedure dictated by the relations of an algebra. We use reduction trees in the subdivision algebra to construct canonical triangulations of flow polytopes which are shellable. We explain how a shelling of the canonical triangulation can be read off from the corresponding reduction tree in the subdivision algebra. We then introduce the notion of shellable reduction trees in the subdivision and related algebras and define h-polynomials of reduction trees. In the case of the subdivision algebra, the h-polynomials of the canonical triangulations of flow polytopes equal the h-polynomials of the corresponding reduction trees, which motivated our definition. We show that the reduced forms in various algebras, which can be read off from the leaves of the reduction trees, specialize to the shifted h-polynomials of the corresponding reduction trees. This yields a technique for proving nonnegativity properties of reduced forms. As a corollary we settle a conjecture of A.N. Kirillov.Comment: 23 pages, 3 figure

The alaas: the interplay between environment and Sakhas in Central-Yakutia

Alaases, thermokarst depressions formed in the permafrost environment of Yakutia (north-eastern Siberia) provide fertile hayfields for the Sakha cattle economy. At this northern latitude, cattle breeding is in particular demand of nutritious fodder, because cows spend an average of nine months in winter-stables. Therefore, alaases are in the focus of Sakha environmental perception. Sakhas not only dwell at alaases, but through their economic activities, they modify and maintain them as well. This process is based on control and domination rather than on procurement of the environment. Villagers in Tobuluk (central Yakutia) consider the areas surrounding their village as controlled islands of alaases (hayfields) in a sea of uncontrolled forest. In this paper, I examine Sakha environmental perception in which landscapes and cardinal directions evoke and define each other and characterise those who reside there. Due to the subsequent transformations of Sakha economy and lifestyle by the Soviet and Russian state administration in the last 100 years (collectivisation, centralisation, and decollectivisation), the way Sakhas interact with their surroundings has transformed radically within the past four generations, causing profound differences in the way generations relate to, interact with, and understand alaases