A dark energy view of inflation

Traditionally, inflationary models are analyzed in terms of parameters such as the scalar spectral index ns and the tensor to scalar ratio r, while dark energy models are studied in terms of the equation of state parameter w. Motivated by the fact that both deal with periods of accelerated expansion, we study the evolution of w during inflation, in order to derive observational constraints on its value during an earlier epoch likely dominated by a dynamic form of dark energy. We find that the cosmic microwave background and large-scale structure data is consistent with w_inflation=-1 and provides an upper limit of 1+w <~ 0.02. Nonetheless, an exact de Sitter expansion with a constant w=-1 is disfavored since this would result in ns=1.Comment: 5 pages, 4 figures; v2: minor modifications to match published versio

On the Topological Resonance Energy of Coumarin and Its Derivates

Topological resonance energies of coumarin and the following derivatives: 3-hydroxycoumarin, 4-hydroxycoumarin, 3,4-dihydro-. xycoumarin, 4,6-dihydroxycoumarin, 4,5,7-trihydroxycoumarin, 3- -carboxy-4-hydroxycoumarin, 3-bromo-4-hydroxycoumarin, and 6-bromo-4-hydroxycoumarin, are reported. Theoretical predictions that these all coumarins should exhibit aromatic properties are sustained by the ample experimental evidence. In addition, coumarin and isocoumarin are predicted to be much more stable than the corresponding quinonoid isomer

RXJ 0921+4529: a binary quasar or gravitational lens?

We report the new spectroscopic observations of the gravitational lens RXJ 021+4529 with the multi-mode focal reducer SCORPIO of the SAO RAS 6-m telescope. The new spectral observations were compared with the previously observed spectra of components A and B of RXJ 0921+4529, i.e. the same components observed in different epochs. We found a significant difference in the spectrum between the components that cannot be explained with microlensing and/or spectral variation. We conclude that RXJ 0921+4529 is a binary quasar system, where redshifts of quasars A and B are 1.6535 +/- 0.0005 and 1.6625 +/- 0.0015, respectively.Comment: 6 pages, 5 figures, accepted for publication in The Astrophysical Journal Letter

Transient Stability Simulation by Waveform Relaxation Methods

In this paper, a new methodology for power system dynamic response calculations is presented. The technique known as the waveform relaxation has been extensively used in transient analysis of VLSI circuits and it can take advantage of new architectures in computer systems such as parallel processors. The application in this paper is limited to swing equations of a large power system. Computational results are presented

Revealing the nature of central emission nebulae in the dwarf galaxy NGC 185

In this paper we present new optical observations of the galaxy NGC 185 intended to reveal the status of supernova remnants (SNRs) in this dwarf companion of the Andromeda galaxy. Previously, it was reported that this galaxy hosts one SNR. Our deep photometric study with the 2m telescope at Rozhen National Astronomical Observatory using narrow-band H$\alpha$ and [SII] filters revealed complex structure of the interstellar medium in the center of the galaxy. To confirm the classification and to study the kinematics of the detected nebulae, we carried out spectroscopic observations using the SCORPIO multi-mode spectrograph at the 6m telescope at the Special Astrophysical Observatory of the Russian Academy of Science, both in low- and high-resolution modes. We also searched the archival X-ray and radio data for counterparts of the candidate SNRs identified by our optical observations. Our observations imply the presence of one more SNR, one possible HII region previously cataloged as part of an SNR, and the presence of an additional source of shock ionization in one low-brightness PN. We detected enhanced [SII]/H_alpha and [NII]/H_alpha line ratios, as well as relatively high (up to 90 km s$^{-1}$) expansion velocities of the two observed nebulae, motivating their classification as SNRs (with diameters of 45 pc and 50 pc), confirmed by both photometric and spectral observations. The estimated electron density of emission nebulae is 30 - 200 cm$^{-3}$. Archival XMM-Newton observations indicate the presence of an extended, low-brightness, soft source in projection of one of the optical SNRs, whereas the archival VLA radio image shows weak, unresolved emission in the center of NGC 185.Comment: 15 pages, 14 figures, accepted for publication in A&

An overview of generalized entropic forms

The aim of this focus letter is to present a comprehensive classification of the main entropic forms introduced in the last fifty years in the framework of statistical physics and information theory. Most of them can be grouped into three families, characterized by two-deformation parameters, introduced respectively by Sharma, Taneja, and Mittal (entropies of degree $(\alpha,\,\beta$)), by Sharma and Mittal (entropies of order $(\alpha,\,\beta)$), and by Hanel and Thurner (entropies of class $(c,\,d)$). Many entropic forms examined will be characterized systematically by means of important concepts such as their axiomatic foundations {\em \`{a} la} Shannon-Khinchin and the consequent composability rule for statistically independent systems. Other critical aspects related to the Lesche stability of information measures and their consistency with the Shore-Johnson axioms will be briefly discussed on a general ground.Comment: 14 pages, 6 tables, no figures, to appear on EPL: Focus Issues "Progresses on Statistical Physics and Complexity

Homodiegetic narration in the Serbian novel ; Гомодиегетическое повествование в сербском романе.

Рад представља покушај теоријског укрштања два различита књижевнонаучна приступа: са једне стране непосредно је заснован на наратолошким поставкама најутицајнијих аутора краја ХХ века (посебно на Женетовој теорији приповедања), док са друге подразумева јасну књижевноисторијску перспективу, и то жанровски прецизно профилисану ‒ организован је као једна специфична повест српског романа. Извршено читалачко истраживање и анализа текстова тежили су да у исто време обухвате и поступке и облике, односно да испитају примену једне посебне приповедне технике (хомодијегетичког приповедања) у конкретној прозној форми (роману) у дужој дијахронијској перспективи. Показало се да је прича о хомодијегетичком роману у исто време и повест српског романа у целини...The work represents an attempt at theoretical cross-section between two different literary scholarship approaches: on the one hand it is indirectly based on narrative settings of the most influential authors of the end of the twentieth century (especially on Genette’s narrative theory), while on the other hand it implies a clear literary-historical perspective which is organized as a specific history of the Serbian novel. The carried out book research and text analyses aspired to comprise both techniques and forms at the same time, i.e. to explore the implementation of a special narrative technique (homodiegetic narration) in a prose form (novel) in a long-term diachronic perspective. The story about the homodiegetic novel has proved to be the history of the Serbian novel at the same time..

The analysis of particles emission during the process of grinding of steel EN 90MNV8

Metal grinding is a one of the manufacturing technologies that is greatly connected to particles emission. Particles generated during the grinding process are dangerous in terms of its potential penetration deeply into the lungs of an operator. The level of risk for human respiratory system is related to nature, shape and size of the particles, and for this reason it is important to have a quality characterization of emitted particles. This paper focuses on particles characterization on the bases of image analysis from scanning electron microscopy (SEM). The research was conducted during the process of grinding of steel EN 90MnV8, using personal sampler. Results of image analysis, consisted of Feret’s diameter and circularity, showed quite a wide range of sizes and significant deviation of particles from regular shape