A5066309834- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Black Holes and Theoretical Physics
- Radio Astronomy Observations and Technology
- Gamma-ray bursts and supernovae
- Particle Detector Development and Performance
- Galaxies: Formation, Evolution, Phenomena
- Relativity and Gravitational Theory
- Particle Accelerators and Free-Electron Lasers
- Advanced Thermodynamics and Statistical Mechanics
- Solar and Space Plasma Dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Chromodynamics and Particle Interactions
- Atomic and Subatomic Physics Research
- Pulsars and Gravitational Waves Research
- Noncommutative and Quantum Gravity Theories
- Lightning and Electromagnetic Phenomena
- High-Energy Particle Collisions Research
- Radiation Detection and Scintillator Technologies
- Ionosphere and magnetosphere dynamics
- Astronomy and Astrophysical Research
- Geophysics and Gravity Measurements
Institute for Nuclear Research
2016-2025
Novosibirsk State University
2014-2024
Université Libre de Bruxelles
2021-2024
Russian Academy of Sciences
1987-2024
Pontifical Catholic University of Rio de Janeiro
2022-2024
Universidade Estadual de Londrina
2022-2024
A. Alikhanyan National Laboratory
2022-2024
Beijing Normal University
2022-2024
China Institute of Atomic Energy
2024
China Academy of Space Technology
2024
We reconsider the old problem of dynamics spontaneous symmetry breaking (SSB) using 3D lattice simulations. develop a theory tachyonic preheating, which occurs due to spinodal instability scalar field. Tachyonic preheating is so efficient that SSB typically completes within single oscillation as field rolls towards minimum its effective potential. show that, contrary previous expectations, in hybrid inflation tachyonic. Our results may also be relevant for formation topological defects and...
We present the first fully non-linear calculation of inflaton decay. map decay onto an equivalent classical problem and solve latter numerically. In $\lambda\phi^4$ model, we find that parametric resonance develops slower ends at smaller values fluctuating fields, as compared to estimates existing in literature. also observe a number qualitatively new phenomena, including stage semiclassical thermalization, during which is essentially effective stage.
We study Bose-Einstein condensation and formation of Bose stars in the virialized dark matter halos/miniclusters by universal gravitational interactions. prove that this phenomenon does occur it is described kinetic equation. give expression for time. Our results suggest may form kinetically mainstream models such as invisible QCD axions Fuzzy Dark Matter.
We analytically solve the problem of Bose star growth in bath gravitationally interacting particles. find that after nucleation this object, is described by a self-similar solution kinetic equation. Together with conservation laws, fixes mass evolution star. Our theory explains, particular, slowdown at certain "core-halo" mass, but also predicts formation heavier and lighter objects magistral dark matter models. The developed "adiabatic" approach to self-similarity may be interest for general.
Evolution of inhomogeneities in the axion field around QCD epoch is studied numerically, including for first time important nonlinear effects. It found that perturbations on scales corresponding to causally disconnected regions at T\ensuremath{\sim}1 GeV can lead very dense clumps, with present density ${\mathrm{\ensuremath{\rho}}}_{\mathit{a}}$\ensuremath{\gtrsim}${10}^{\mathrm{\ensuremath{-}}8}$ g ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$. This high enough collisional...
We show that gravitational radiation is produced quite efficiently in interactions of classical waves created by resonant decay a coherently oscillating field. As an important example we consider simple models chaotic inflation, where find today's ratio energy density per octave to the critical Universe can be as large ${10}^{\ensuremath{-}12}$ at maximal wavelength order ${10}^{5}$ cm. In pure $\ensuremath{\lambda}{\ensuremath{\varphi}}^{4}/4$ model with inflaton self-coupling...
We use simulations of LSS formation to study the build-up magnetic fields (MFs) in ICM. Our basic assumption is that cosmological MFs grow a MHD amplification process driven by structure out seed MF present at high z. LCDM initial conditions for density fluctuations have been statistically constrained observed galaxies, based on IRAS 1.2-Jy all-sky redshift survey. As result, prominent galaxy clusters our simulation coincide closely with their real counterparts. find excellent agreement...
This is a systematic study of the evolution thin shell bubbles in general relativity. We develop thin-wall formalism first elaborated by Israel and apply it to investigation motion various arising course phase transitions very early Universe including new bubbles, old remnants, domains. consider metric junction conditions derive constraints both on decay metastable states non- equilibrium scalar field configurations (fluctuations) following from global geometry spacetime.
The $(3+1)$-dimensional evolution of an inhomogeneous axion field configuration around the QCD epoch is studied numerically, including important non-linear effects due to attractive self-interaction. It found that perturbations on scales corresponding causally disconnected regions at $T \sim 1 \, {\rm GeV}$ can lead very dense pseudo-soliton configurations we call axitons. These evolve miniclusters with present density $\rho_a \ga 10^{-8}\,{\rm g cm^{-3}}$. This high enough for collisional...
We study, analytically and with lattice simulations, the decay of coherent field oscillations subsequent thermalization resulting stochastic classical wave field. The problem reheating Universe after inflation constitutes our prime motivation application results. identify three different stages these processes. During initial stage ``parametric resonance,'' only a small fraction inflaton energy is transferred to fluctuations in physically relevant case sufficiently large couplings. A major...
The phenomenon of the resonant production particles after inflation has received much attention in past few years. In a new application particles, we consider effect resonance during inflation. We show that if inflaton is coupled to massive particle, particle modifies evolution inflaton, and may leave an imprint form sharp features primordial power spectrum. Precision measurements microwave background anisotropies large-scale structure surveys could be sensitive features, probe spectrum as...
The process of condensation in the system scalar Bosons with weak $\lambda \phi^4$ interaction is considered. Boltzmann kinetic equation solved numerically. Bose proceeds two stages: At first stage condensate still absent but there non-zero inflow particles towards $\vec{{\bf p}} = 0$ and distribution function at grows from finite values to infinity. second are components, particles, reaching their equilibrium values. We show that evolution both stages a self - similar way find time needed...
We study, both numerically and analytically, the development of equilibrium after preheating. show that process is characterized by appearance Kolmogorov spectra evolution towards thermal follows self-similar dynamics. Simplified kinetic theory gives values for all characteristic exponents which are close to what observed in lattice simulations. The resulting time thermalization long, temperature at low, $T\ensuremath{\sim}100\text{ }\text{ }\mathrm{e}\mathrm{V}$ simple...
We propose a strategy for how to look dark matter particles possessing radiative decay channel and derive constraints on their parameters from observations of x rays our own Galaxy its dwarf satellites. When applied sterile neutrinos in the keV mass range this approach gives significant improvement restrictions neutrino compared with previous works.
The substructures of light bosonic (axionlike) dark matter may condense into compact Bose stars. We study the collapse critical-mass stars caused by attractive self-interaction axionlike particles and find that these processes proceed in an unexpected universal way. First, nonlinear self-similar evolution (called "wave collapse" condensed physics) forces to fall star center. Second, interactions dense center create outgoing stream mildly relativistic which carries away essential part mass....
We revisit cosmic microwave background (CMB) constraints on the abundance of millicharged particles based Planck data. The stringent limit Omega_{mcp}h^2 < 0.001 (95% CL) may be set using CMB data alone if participate in acoustic oscillations baryon-photon plasma at recombination epoch. latter condition is valid for a wide region charges and masses particles. Adding component to LCDM shifts prefered scalar spectral index primordial perturbations somewhat larger values as compared minimal...
We review the physics potential of a next generation search for solar axions: International Axion Observatory (IAXO) . Endowed with sensitivity to discover axion-like particles (ALPs) coupling photons as small gaγ∼ 10−12 GeV−1, or electrons gae∼10−13, IAXO has find QCD axion in 1 meV∼1 eV mass range where it solves strong CP problem, can account cold dark matter Universe and be responsible anomalous cooling observed number stellar systems. At same time, will have enough detect lower axions...
We show that emerging tension between the direct astronomical measurements at low redshifts and cosmological parameters deduced from Planck of CMB anisotropies can be alleviated if dark matter consists two fractions, stable part being dominant a smaller unstable fraction. The latter constitutes $\sim 10$ per cent recombination epoch decays by now.
It has been recently suggested~\cite{Berezhiani:2015yta} that emerging tension between cosmological parameter values derived in high-redshift (CMB anisotropy) and low-redshift (cluster counts, Hubble constant) measurements can be reconciled a model which contains subdominant fraction of dark matter decaying after recombination. We check the against CMB Planck data. find lensing anisotropies by large-scale structure gives strong extra constraints on this model, limiting as $F<8\%$ at...
Abstract We present a new experimental study of the quantum entanglement photon pairs produced in positron-electron annihilation at rest. Each has an energy that is five orders magnitude higher than photons optical experiments. It provides unique opportunity for controlled Compton pre-scattering initial before polarization measurements. The setup includes system polarimeters to measure angular correlations and thus prepared pre-scattered states. For first time, direct comparison been carried...
Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come extragalactic sources. Their arrival is infrequent, so detection requires instruments large collecting areas. In this work, we report of an extremely particle recorded by surface detector array Telescope Array experiment. We calculate particle's energy as [Formula: see text] (~40 joules). Its direction points back a void in large-scale structure Universe. Possible...