Dissipation in the hagedorn early universe

The viscosity coefficients of the Hagedorn hadronic matter are obtained by solving the Boltzmann kinetic equation in the relaxation-time approximation. The upper limit for the increase of entropy per baryonic charge was found to be < 10$^{-4}$ in the "hadron era" of the Friedman universe and the model behaves almost like dust-filled models. There is no anisotropy damping in the Bianchi type I universe but a substantial growth of entropy is possible in that era when anisotropy has an extremely high value

Cosmic-Ray Acceleration at Ultrarelativistic Shock Waves: Effects of Downstream Short-Wave Turbulence

The present paper is the last of a series studying the first-order Fermi acceleration processes at relativistic shock waves with the method of Monte Carlo simulations applied to shocks propagating in realistically modeled turbulent magnetic fields. The model of the background magnetic field structure of Niemiec & Ostrowski (2004, 2006) has been augmented here by a large-amplitude short-wave downstream component, imitating that generated by plasma instabilities at the shock front. Following Niemiec & Ostrowski (2006), we have considered ultrarelativistic shocks with the mean magnetic field oriented both oblique and parallel to the shock normal. For both cases simulations have been performed for different choices of magnetic field perturbations, represented by various wave power spectra within a wide wavevector range. The results show that the introduction of the short-wave component downstream of the shock is not sufficient to produce power-law particle spectra with the "universal" spectral index 4.2. On the contrary, concave spectra with cutoffs are preferentially formed, the curvature and cutoff energy being dependent on the properties of turbulence. Our results suggest that the electromagnetic emission observed from astrophysical sites with relativistic jets, e.g. AGN and GRBs, is likely generated by particles accelerated in processes other than the widely invoked first-order Fermi mechanism.Comment: 9 pages, 8 figures, submitted to Ap

Study of GRB light curve decay indices in the afterglow phase

In this work we study the distribution of temporal power-law decay indices, $\alpha$, in the Gamma Ray Burst (GRB) afterglow phase, fitted for $176$ GRBs (139 long GRBs, 12 short GRBs {\it with extended emission} and 25 X-Ray Flashes (XRFs)) with known redshifts. These indices are compared with the temporal decay index, $\alpha_W$, derived with the light curve fitting using the \cite{willingale07} model. This model fitting yields similar distributions of $\alpha_W$ to the fitted $\alpha$, but for individual bursts a difference can be significant. Analysis of ($\alpha$, $L_a$) distribution, where $L_a$ is the characteristic luminosity at the end of the plateau, reveals only a weak correlation of these quantities. However, we discovered a significant regular trend when studying GRB $\alpha$ values along the \cite{dainotti2008} correlation between $L_a$ and the end time of the plateau emission in the rest frame, $T_a^*$, hereafter LT correlation. We note a systematic variation of the $\alpha$ parameter distribution with luminosity for any selected $T_a^*$. We analyze this systematics with respect to the fitted LT correlation line, expecting that the presented trend may allow to constrain the GRB physical models. We also attempted to use the derived correlation of $\alpha(T_a)$ versus $L_a(T_a)$ to diminish the luminosity scatter related to the variations of $\alpha$ along the LT distribution, a step forward in the effort of standardizing GRBs. A proposed toy model accounting for this systematics applied to the analyzed GRB distribution results in a slight increase of the LT correlation coefficient.Comment: Accepted for publication in Ap

Longterm Optical Monitoring of Bright BL Lacertae Objects with ATOM: Spectral Variability and Multiwavelength Correlations

Blazars are the established sources of an intense and variable non-thermal radiation extending from radio wavelengths up to HE and VHE gamma-rays. Understanding the spectral evolution of blazars in selected frequency ranges, as well as multi-frequency correlations in various types of blazar sources, is of a primary importance for constraining the blazar physics. Here we present the results of a long-term optical monitoring of a sample of 30 blazars of the BL Lac type. We study the optical color-magnitude correlation patterns emerging in the analyzed sample, and compare the optical properties of the targets with the high-energy gamma-ray and high-frequency radio data. The optical observations were carried out in R and B filters using ATOM telescope. Each object was observed during at least 20 nights in the period 2007-2012. We find significant global color-magnitude correlations in 40 % of the sample. The sources which do not display any clear chromatism often do exhibit bluer-when-brighter (bwb) behavior but only in isolated shorter time intervals. We also discovered spectral state transitions at optical wavelengths in several sources. Finally, we find that the radio, optical, and gamma-ray luminosities of the sources obey almost linear correlations, which seem however induced, at least partly, by the redshift dependance, and may be also affected by non-simultaneousness of the analyzed dataset. We argue that the observed bwb behavior is intrinsic to the jet emission regions, at least for some of the analyzed blazars, rather than resulting from the contamination of the measured flux by the starlight of host galaxies. We also conclude that the significance of color-magnitude scalings does not correlate with the optical color, but instead seems to depend on the source luminosity, in a sense that these are the lowest-luminosity BL Lac objects which display the strongest correlations.Comment: 16 pages, 9 figures, accepted for publication in Astronomy & Astrophysic

Cosmic-ray Acceleration at Ultrarelativistic Shock Waves: Effects of a "Realistic" Magnetic Field Structure

First-order Fermi acceleration processes at ultrarelativistic shocks are studied with Monte Carlo simulations. The accelerated particle spectra are derived by integrating the exact particle trajectories in a turbulent magnetic field near the shock. ''Realistic'' features of the field structure are included. We show that the main acceleration process at superluminal shocks is the particle compression at the shock. Formation of energetic spectral tails is possible in a limited energy range only for highly perturbed magnetic fields, with cutoffs occuring at low energies within the resonance energy range considered. These spectral features result from the anisotropic character of particle transport in the downstream magnetic field, where field compression produces effectively 2D perturbations. Because of the downstream field compression, the acceleration process is inefficient in parallel shocks for larger turbulence amplitudes, and features observed in oblique shocks are recovered. For small-amplitude turbulence, wide-energy range particle spectra are formed and modifications of the process due to the existence of long-wave perturbations are observed. In both sub- and superluminal shocks, an increase of \gamma leads to steeper spectra with lower cut-off energies. The spectra obtained for the ``realistic'' background conditions assumed here do not converge to the ``universal'' spectral index claimed in the literature. Thus the role of the first-order Fermi process in astrophysical sources hosting relativistic shocks requires serious reanalysis.Comment: submitted to Ap

Comparison of the results of modified NDVI indicator established on the basis of measurements by hyperspectral spectrometer and digital camera

Due to the lack of readily available imaging remote sensing methods that would determine the vegetation state on a local scale, an attempt was made to calculate the modified NDVI index on the basis of digital camera photography. To verify the effectiveness of the method, the digital camera and hyperspectral spectrometer results were compared. For the analysis material leaves of six different tree species from an urban area were selected and picked in four different phases of the vegetative season. The results prove that there is no significant correlation between the two methods, but they also suggest that further research on the proposed method is necessary.

Problem wydatków sztywnych w budżecie państwa oraz zmieniającym się środowisku polskich finansów publicznych

This article deals with a problem of budget rigidities. At the outset, the doctrinal definitions of budged rigidities were cited and analyzed. On this basis, the Author developed a catalogue of rigidities, the elements of which were later classified into appropriate expenditure groups. In the further part of the work, methods of making ridged expenses more flexible are presented. Then, the problem of an excessive increase in budged rigidities is presented in the context of the marginalization of the state budget process that has been progressing in recent years. On the basis of the current processes taking place in the fiscal policy, the author indicates the need to consider the described problem in a wider context.W artykule wskazano problem państwowych wydatków sztywnych. Na wstępie przytoczone i przeanalizowane zostały doktrynalne definicje wydatków sztywnych. Na tej podstawie opracowano katalog wydatków sztywnych, którego elementy później zostały zaklasyfikowane do odpowiednich grup wydatkowych. W dalszej części pracy przytoczone są metody „uelastyczniania wydatków sztywnych” w zależności od ich źródła. Następnie problem nadmiernego wzrostu wydatków sztywnych zestawiony zostaje z postępującą w ostatnich latach marginalizacją budżetu państwa. Na podstawie obecnych procesów zachodzących w polityce fiskalnej wskazano na konieczność rozpatrywania opisywanego problemu w szerszym obszarze niż budżet państwa

Modyfikacje konstrukcji stabilizującej reguły wydatkowej w 2021 roku

This article is focused on an analysis of amendments introduced to Articles 112aa and 112d of the Public Finance Act which were adopted by Act of 11 August 2021 amending the Public Finance Act and certain other acts. At the beginning, a structure of the stabilising expenditure rule mechanism is briefly described. In this part of the text first-made changes are also outlined. Then, reasons for introducing subsequent amendments and form of each of these changes are thoroughly analysed. On this basis, conclusions are drawn as to the impact of the modification on the functioning of the stabilizing expenditure rule in the following years.Przedmiotem artykułu jest analiza zmian w art. 112aa i art. 112d ustawy o finansach publicznych, które zostały uchwalone na mocy ustawy z dnia 11 sierpnia 2021 r. o zmianie ustawy o finansach publicznych oraz niektórych innych ustaw. Na wstępie krótkiemu opisowi została poddana konstrukcja mechanizmu SRW oraz nakreślone zostały jego wcześniejsze zmiany. Następnie dogłębnej analizie poddane zostały przyczyny i forma każdej z omawianych zmian. Na tej podstawie zostały wyciągnięte wnioski co do wpływu modyfikacji na funkcjonowanie stabilizującej reguły wydatkowej w następnych latach