It is shown that the problem of evaluating the continuous Morlet wavelet transform can be stated as the Cauchy problem for a system of two partial differential equations. The initial conditions for ...the desired functions, i.e., for the real and imaginary parts of the wavelet transform, are the analyzed function and a vanishing function, respectively. Numerical examples are given.PUBLICATION ABSTRACT
It is shown that time-scale synchronization of chaotic systems with ill-defined conventional phase is achieved by using wavelet transforms with center frequencies above a certain threshold value. It ...is found that the possibility of synchronization detection by introducing a wavelet phase is related to diffusion averaging of the analyzed signals.
The prototype of a small wide-angle telescope was installed within the astrophysical complex TAIGA in the Tunka Valley in September 2019. Data were collected on the prototype’s performance during the ...last eight observation sessions. Operating regimes of the telescope’s systems, the trigger system, and the system for synchronizing with the TAIGA complex were tested. The first results from analyzing data on the prototype telescope’s performance are presented.
A combined approach to distinguishing extensive atmospheric showers (EASes) from gamma rays, based on analyzing Imaging Atmospheric Cherenkov Telescope (IACT) images and shower parameters ...reconstructed using data from a nonimaging (timing) array, is investigated. The study is conducted with simulated data on the registration of Cherenkov radiation from an EAS. The optimum set of combined parameters, the efficiency of the multivariate approach, and the dependence of the background suppression factor on energy and distance are determined. The findings are compared to those from the operation of an isolated IACT. It is shown that in the >50 TeV range of energies, the background can be suppressed by a factor of 100 even at distances of up to 450 m from an IACT telescope.
A simple “knee-like” approximation of the Lateral Distribution Function (LDF) of Cherenkov light emitted by EAS (extensive air showers) in the atmosphere is proposed for solving various tasks of data ...analysis in HiSCORE and other wide angle ground-based experiments designed to detect gamma rays and cosmic rays with the energy above tens of TeV. Simulation-based parametric analysis of individual LDF curves revealed that on the radial distance 20−500 m the 5-parameter “knee-like” approximation fits individual LDFs as well as a mean LDF with a very good accuracy. In this paper we demonstrate the efficiency and flexibility of the “knee-like” LDF approximation for various primary particles and shower parameters and the advantages of its application to suppressing proton background and selecting primary gamma rays.
A strong excess in a form of a wide peak in the energy range of 300-800 GeV was discovered in the first measurements of the electron spectrum in the energy range from 20 GeV to 3 TeV by the ...balloon-borne experiment ATIC (Chang et al., 2008b). The experimental data processing and analysis of the electron spectrum with different criteria for selection of electrons, completely independent of the results reported in Chang et al. (2008b) is employed in the present paper. The new independent analysis generally confirms the results of Chang et al. (2008b), but shows that the spectrum in the region of the excess is represented by a number of narrow peaks. The measured spectrum is compared to the spectrum of Chang et al. (2008b) and to the spectrum of the Fermi/LAT experiment.
The relevance and benefits of the new TAIGA gamma observatory complex in the Tunka Valley (50 km from Lake Baikal) are discussed. The main aim of the TAIGA installation is to study high-energy gamma ...radiation and search for cosmic pevatrons. The first series of gamma stations was commissioned in 2019 and covers an area of 1 km
2
. Its expected integral gamma radiation sensitivity at an energy of 100 TeV over 300 h of source monitoring is (2–5) × 10
−13
TeV cm
−2
s
−1
. It is planned to expand the effective area of TAIGA gamma observation to 10 km
2
in the future.
A corrected energy dependence of the depth of the maximum in the wide range of energies 10
15
to 10
18
eV is obtained using data collected at the Tunka-133 facility over 7 years of operation ...(2009–2017) and the TAIGA-HiSCORE facility in the 2019–2020 season. At the highest energies, our results match those of the Pierre Auger observatory. The results are converted to parameter ❬ln
A
❭, which characterizes the mean EAS composition.
The data (the speed of sound, the isobaric and isochoric heat capacities, as well as the heat capacity ratio) for liquid neon presented in the NIST Chemistry WebBook are analyzed. It has been shown, ...based on the representation of the inverse reduced volume fluctuations, that they consist of sufficient discrepancies in the subcritical region. The correction of data in this region of the coexistence curve is evaluated using the fluctuation approach and the theory of thermodynamic similarity.
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