Publications by authors named "I A Tkachev"
We report an estimation of the injected mass composition of ultrahigh energy cosmic rays (UHECRs) at energies higher than 10 EeV. The composition is inferred from an energy-dependent sky distribution of UHECR events observed by the Telescope Array surface detector by comparing it to the Large Scale Structure of the local Universe. In the case of negligible extragalactic magnetic fields (EGMFs), the results are consistent with a relatively heavy injected composition at E∼10 EeV that becomes lighter up to E∼100 EeV, while the composition at E>100 EeV is very heavy.
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- The study provides an analytical solution for Bose star growth within a system of gravitationally interacting particles.
- After the formation of the Bose star, the surrounding particle bath follows a self-similar behavior described by a kinetic equation, which influences the mass changes of the star.
- The findings not only clarify why star growth slows down at a specific mass but also suggest the potential formation of various mass objects in dark matter scenarios.
Article Synopsis
- - Cosmic rays are high-energy charged particles from space, with the most intense ones believed to originate outside our galaxy.
- - The Telescope Array experiment has successfully detected an extremely energetic particle, estimated to have an energy of about 40 joules.
- - The particle’s trajectory leads to a gap in the universe's structure, raising questions about its source, including potential magnetic field interference or gaps in our understanding of particle physics.
The study of the optical properties of cirrus clouds is necessary to improve the accuracy of interpreting data from space lidars and ground-based lidar networks. Existing databases of backscattering properties do not include data on hollow columns. In this paper, the backscattering properties of randomly oriented hollow column ice crystal particles in cirrus at wavelengths of 355 nm, 532 nm, and 1064 nm have been investigated.
View Article and Find Full Text PDFWe present a new experimental study of the quantum entanglement of photon pairs produced in positron-electron annihilation at rest. Each annihilation photon has an energy that is five orders of magnitude higher than the energy of photons in optical experiments. It provides a unique opportunity for controlled Compton pre-scattering of initial photons before the polarization measurements.
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