Corrections to Hawking-like Radiation for a Friedmann-Robertson-Walker Universe

Recently, a Hamilton-Jacobi method beyond semiclassical approximation in black hole physics was developed by \emph{Banerjee} and \emph{Majhi}\cite{beyond0}. In this paper, we generalize their analysis of black holes to the case of Friedmann-Robertson-Walker (FRW) universe. It is shown that all the higher order quantum corrections in the single particle action are proportional to the usual semiclassical contribution. The corrections to the Hawking-like temperature and entropy of apparent horizon for FRW universe are also obtained. In the corrected entropy, the area law involves logarithmic area correction together with the standard inverse power of area term.Comment: 10 pages, no figures, comments are welcome; v2: references added and some typoes corrected, to appear in Euro.Phys.J.C; v3:a defect corrected. We thank Dr.Elias Vagenas for pointing out a defect of our pape

Unruh--DeWitt detectors in spherically symmetric dynamical space-times

In the present paper, Unruh--DeWitt detectors are used in order to investigate the issue of temperature associated with a spherically symmetric dynamical space-times. Firstly, we review the semi-classical tunneling method, then we introduce the Unruh--DeWitt detector approach. We show that for the generic static black hole case and the FRW de Sitter case, making use of peculiar Kodama trajectories, semiclassical and quantum field theoretic techniques give the same standard and well known thermal interpretation, with an associated temperature, corrected by appropriate Tolman factors. For a FRW space-time interpolating de Sitter space with the Einstein--de Sitter universe (that is a more realistic situation in the frame of $\Lambda$CDM cosmologies), we show that the detector response splits into a de Sitter contribution plus a fluctuating term containing no trace of Boltzmann-like factors, but rather describing the way thermal equilibrium is reached in the late time limit. As a consequence, and unlike the case of black holes, the identification of the dynamical surface gravity of a cosmological trapping horizon as an effective temperature parameter seems lost, at least for our co-moving simplified detectors. The possibility remains that a detector performing a proper motion along a Kodama trajectory may register something more, in which case the horizon surface gravity would be associated more likely to vacuum correlations than to particle creation.Comment: 19 pages, to appear on IJTP. arXiv admin note: substantial text overlap with arXiv:1101.525

On exact solutions for quantum particles with spin S= 0, 1/2, 1 and de Sitter event horizon

Exact wave solutions for particles with spin 0, 1/2 and 1 in the static coordinates of the de Sitter space-time model are examined in detail. Firstly, for a scalar particle, two pairs of linearly independent solutions are specified explicitly: running and standing waves. A known algorithm for calculation of the reflection coefficient $R_{\epsilon j}$ on the background of the de Sitter space-time model is analyzed. It is shown that the determination of R_{\epsilon j} requires an additional constrain on quantum numbers \epsilon \rho / \hbar c >> j, where \rho is a curvature radius. When taken into account of this condition, the R_{\epsilon j} vanishes identically. It is claimed that the calculation of the reflection coefficient R_{\epsilon j} is not required at all because there is no barrier in an effective potential curve on the background of the de Sitter space-time. The same conclusion holds for arbitrary particles with higher spins, it is demonstrated explicitly with the help of exact solutions for electromagnetic and Dirac fields.Comment: 30 pages. This paper is an updated and more comprehensive version of the old paper V.M. Red'kov. On Particle penetrating through de Sitter horizon. Minsk (1991) 22 pages Deposited in VINITI 30.09.91, 3842 - B9

НИЖНЬОКРЕЙДОВІ АПТИХИ (AMMONOIDEA) АЗЕРБАЙДЖАНУ: ОСНОВНІ ЗАКОНОМІРНОСТІ ПРОСТОРОВО-ЧАСОВОГО РОЗПОДІЛУ

A monographic study of the Lower Cretaceous Aptychi (Ammonoidea) in Azerbaijan has revealed their complete systematic composition: 6 genera and subgenera, 62 species and subspecies. The Lower Cretaceous Aptychi assemblages recognized in Azerbaijan are well correlated with those of the Crimea, the Carpathians, the Alps and the Caribbean.Монографическое изучение нижнемеловых аптихов (Ammonoidea) Азербайджана позволило выявить их наиболее полный систематический состав: 6 таксонов родовой,  62 таксона видовой группы. Выделенные нижнемеловые комплексы аптихов Азербайджана хорошо сопоставляются с таковыми Крыма, Карпат, Альп, Карибского бассейна.Монографічне вивчення нижньокрейдових аптихів (Ammonoidea) Азербайджану дозволило виявити найбільш повний систематичний склад: шість таксонів родової, 62 таксони видової групи. Виділені нижньокрейдові комплекси аптихів Азербайджану добре зіставляються з такими Криму, Карпат, Альп, Карібського басейну

ЮРСЬКІ HIPPURITOIDA (BIVALVIA) МАЛОГО КАВКАЗУ: СИСТЕМАТИЧНИЙ СКЛАД І ПИТАННЯ ПРОСТОРОВО-ЧАСОВОГО РОЗПОДІЛУ

A monographic study of Jurassic representatives of the order Hippuritoida of the Lesser Caucasus allowed us to identify 27 species belonging to 11 genera: Pachyrisma (2 species) Pteriocardium (1), Diceras (6), Macrodiceras (1), Eodiceras (2), Epidiceras (3), Heterodiceras (5), Mesodiceras (2), Paradiceras (2), Megadiceras (1), Hypelasma (1). The Lesser Caucasus has been found to be one of the centers of rudists’ speciation in the Late Jurassic.Монографическое изучение юрских представителей отряда Hippuritoida Малого Кавказа позволило установить 27 видов, относящихся к 11 родам: Pachyrisma (2 вида) Pteriocardium (1), Diceras (6), Macrodiceras (1), Eodiceras (2), Epidiceras (3), Heterodiceras (5), Mesodiceras (2), Paradiceras (2), Megadiceras (1), Hypelasma (1). Установлено, что одним из центров видообразования позднеюрских рудистов являлся Малый Кавказ.Монографічне вивчення юрских представників ряду Hippuritoida Малого Кавказу дозволило встановити 27 видів, які відносяться до 11 родів: Pachyrisma (два види) Pteriocardium (один), Diceras (шість), Macrodiceras (один), Eodiceras (два), Epidiceras (три), Heterodiceras (п’ять), Mesodiceras (два), Paradiceras (два), Megadiceras (один), Hypelasma (один). Встановлено, що одним з центрів видоутворення пізньоюрських рудистів є Малий Кавказ

VEGETATIVE STATUS AND CORTISOL LEVEL IN SCHOOL AGE CHILDREN WITH NORMAL, HIGH NORMAL ARTERIAL PRESSURE AND ESSENTIAL ARTERIAL HYPERTENSION

Essential arterial hypertension (EAH) among teenagers is a predictor of hypertonic disease in adults, risk factor of heart ischemic disease development, atherosclerosis, cardiac failure, which are basic reasons of invalidity and mortality of adult population. In relation to that, problem of prevention and prognosis of the progression of high normal pressure and arterial hypertension in children and teenagers occupies prior position in pediatrics and children’s cardiology

VEGETATIVE STATUS AND CORTISOL LEVEL IN SCHOOL AGE CHILDREN WITH NORMAL, HIGH NORMAL ARTERIAL PRESSURE AND ESSENTIAL ARTERIAL HYPERTENSION

Essential arterial hypertension (EAH) among teenagers is a predictor of hypertonic disease in adults, risk factor of heart ischemic disease development, atherosclerosis, cardiac failure, which are basic reasons of invalidity and mortality of adult population. In relation to that, problem of prevention and prognosis of the progression of high normal pressure and arterial hypertension in children and teenagers occupies prior position in pediatrics and children’s cardiology