arXiv subjects

M. Yu. Khlopov

Publications and source records attributed to M. Yu. Khlopov.

At least 19 recordsLinked to original sources

arXiv2026

Tracing Inflationary Imprints Through the Dark Ages: Implications for Early Stars and Galaxies Formation

We explore how inflationary features shape the early stages of cosmic structure formation. Using the transfer function formalism, we trace the evolution of primordial perturbations, showing how causal physics and oscillatory signatures from inflation influence the matter power spectrum. The variance of smoothed density fields is then applied to model the collapse of overdense regions and predict dark matter halo abundances through the Press-Schechter framework. Extending to the baryonic sector, we analyze primordial gas collapse in minihalos, emphasizing molecular hydrogen cooling and the thermochemical pathways leading to Population III star formation. Finally, we examine primordial black holes as potential seeds for early galaxies, connecting their accretion-driven growth to the stellar masses and disk properties of high-redshift systems. Our results indicate that oscillatory features from inflation can leave measurable imprints on halo abundances and early galaxy properties, providing a testable link between high-energy physics and astrophysical observations with JWST

gr-qc↗

arXiv2025

Anomalous Isotopes In Dark Atoms models

In this work, we study some aspects of the dark atom model. We consider a finite-size nucleus to find the wave functions of the bound state of a stable particle with a charge of $-2n$ and helium-4 $^4He^{++}$. Then we address the problem of calculating the abundance of anomalous isotopes arising from the capture of helium nuclei by dark atoms during Big Bang nucleosynthesis. We use an analogy with the proton-neutron capture process to calculate the reaction cross section and thus determine the concentration of OBe nuclei.

hep-ph↗

arXiv2025

The bound state of dark atom with the nucleus of substance

The hypothesis of composite $XHe$ dark atoms offers a compelling framework to address the challenges in direct dark matter particles detection, as their neutral, atom-like configuration evades conventional experimental signatures. A critical issue may arise in interaction between $XHe$ and atomic nuclei due to the unshielded nuclear attraction, which could destabilize the dark atom's bound state. To resolve this, we propose a novel numerical quantum mechanical approach that accounts for self-consistent electromagnetic-nuclear couplings. This method addresses to eliminate the inherent complexity of the $XHe$-nucleus three-body system, where analytical solutions are intractable. By reconstructing the effective interaction potential - including dipole Coulomb barrier and shallow potential well - we demonstrate how these features lead to the formation of $XHe$-nucleus bound states and modulate low-energy capture processes. Our model enables validation of the dark atom hypothesis, particularly in interpreting experimental anomalies like annual modulation signals observed in DAMA/LIBRA. These findings advance the theoretical foundation for dark matter interactions and provide a robust framework for future experimental design.

hep-ph↗

arXiv2025

Quantum-mechanical numerical model of interaction between dark atom and nucleus of substance

The hypothesis of composite $XHe$ dark atoms may provide solution to the long-standing problem of direct searches for dark matter particles. The main problem of the $XHe$ dark atom is its ability to strongly interact with the nucleus of substance, arising from the unshielded nuclear attraction between the helium nucleus and the nucleus of matter. It is assumed that in order to prevent the destruction of the bound structure of dark atom, the effective potential of interaction between $XHe$ and the nucleus of substance must have dipole Coulomb barrier that prevents the fusion of dark matter atom particles with the nucleus of substance. The problem in describing the interaction between dark atom and substance nucleus is the three-body problem, for which an exact analytical solution is not available. Consequently, to assess the physical meaning of the proposed scenario, it is essential to develop a numerical approach. Our approach involves consistently developing an accurate quantum mechanical description of this three-body system, comprising bound dark atom and the external nucleus of substance. We incorporate the necessary effects and interactions to enhance the precision of the results, which helps to elucidate the most significant aspects of the proposed dark atom scenario.

hep-ph↗

arXiv2025

Cosmology in the De Donder-Weyl Formulation of Einstein-Cartan Gravity

We investigate torsion-driven cosmological dynamics within the framework of Einstein-Cartan gravity using the De Donder-Weyl Hamiltonian formalism, where the tetrad and Lorentz connection act as independent variables and the Hamiltonian includes quadratic Riemann Cartan corrections. Embedding this theory in an FLRW background, we derive the corresponding torsion-modified Friedmann equations and analyze their solutions across radiation and matter-dominated epochs. The commonly assumed power law form $a(t)=βt^α$ is shown to generate multiple solution branches, many of which can be considered to be 'unphysical'. A hybrid solution, $a(t)=Ct^αe^{Dt^β}$ emerges in the special case $g_1=0$, where the quadratic Riemann-Cartan term vanishes. For $g_1\not=0,$ the equations become nonlinear, precluding closed-form analytic solutions. These findings highlight the limitations of the power-law approximation and identify the restricted conditions under which torsion can coherently drive cosmic expansion.

gr-qc↗

arXiv2025

Unified Pati-Salam from Noncommutative Geometry: Overview and Phenomenological Remarks

The lack of clear new-physics signals at the LHC searches motivates models that can guide current and future collider searches. The spectral action principle within the noncommutative geometry (NCG) framework yields such models with distinctive phenomenology. This formalism derives the actions of the Standard Model, General Relativity, and beyond from the underlying algebra, putting them on a common geometric footing. Certain versions of Pati-Salam (PS) models with gauge coupling unification and limited scalar content can be derived from an appropriate noncommutative algebra. In this paper, I review these gauge-coupling-unified Pati-Salam models and discuss their phenomenological aspects, focusing on the $S_1$ scalar leptoquark.

hep-ph↗

arXiv2025

Do we understand the internal spaces of second quantized fermion and boson fields, with gravity included? Relation with strings theories

The article proposes the description of internal spaces of fermion (quarks and leptons and antiquarks and antileptons) and boson (photons, weak bosons, gluons, gravitons and scalars) second quantized fields in a unique way if they all are massless. The internal spaces are described by ``basis vectors'', which are the superposition of odd (for fermions) and even (for bosons) products of the operators $γ^ {a}$. For an arbitrary symmetry $SO(d-1,1)$ of the internal spaces, it is the number of fermion fields (they appear in families and have their Hermitian conjugated partners in a separate group) equal to the number of boson fields (they appear in two orthogonal groups), manifesting a kind of supersymmetry, which differ of the string supersymmetry. On the assumption that fermions and bosons are active (they have momenta different from zero) only in $d=(3+1)$ ordinary space-time, bosons present vectors if they carry the space index $μ=(0,1,2,3)$, and present scalars if they carry the index $σ\ge 5$. The author discusses this theory's latest achievements, with a trial to understand whether the extension to strings or to odd-dimensional spaces can lead to a new kind of supersymmetry. This model, named {\it spin-charge-family} theory, manifests in a long series of papers on the phenomenological success of the theory in elementary particle physics and cosmology.

physics.gen-ph↗

arXiv2024

Problems of dark atom cosmology

The dark atoms $XHe$ are the composite Thomson like atomic dark matter candidates. We address two cosmological problems of this model. The excess of new superheavy particles with even negative charge $X^{-2n}$ over the corresponding antiparticles is balanced by sphaleron transitions with baryon asymmetry and the mass range of $X$ particles should be specified at which this excess can provide dominance of dark atoms in the dark matter density. The other problem is possible capture of light nuclei by dark atoms, which can lead to formation of anomalous isotopes. The possibility of formation of multi dark atom systems at the nucleosynthesis stage is also studied. We approach these open questions of dark atom cosmology in the present work.

hep-ph↗

arXiv2024

Leptogenesis Effects on the Gravitational Waves Background: Interpreting the NANOGrav Measurements and JWST Constraints on Primordial Black Holes

We demonstrate that the leptogenesis mechanisms, which are associated with B-L symmetry breaking mechanism has notable effects on the production of gravitational waves. These gravitational waves align well with the recent observations of a stochastic gravitational wave background by NANOGrav and pulsar-timing arrays (PTAs). For these gravitational waves to match the recent measurements, the critical value of the B-L breaking should be around the GUT scale. Moreover, we consider the generation of primordial gravitational waves from binary systems of Primordial Black Holes (PBHs) which could be predicted by the recent detection of gravitational waves. PBHs with specific masses can be responsible for massive galaxy formation observed at high redshifts reported by the James Webb Space Telescope (JWST). We contemplate the potential for a shared source between the NANOGrav and JWST observations, namely primordial black holes. These black holes could serve as seeds of rapid galaxy formation, offering an explanation for the galaxies observed by JWST.

gr-qc↗

arXiv2024

Balancing baryon and asymmetric dark matter excess

Effect of the electroweak non-conservation of the baryon number could be a key ingredient to explain the ratio of dark and baryonic densities. If dark matter is explained by dark atoms, in which stable -2n charged particles are bound with n nuclei of primordial helium, and this multiple charged particles possess SU(2) electroweak charges, the excess of -2n charged particles over their antiparticles can be related to baryon excess by sphaleron transitions. It provides relationship between the density of asymmetric dark atom dark matter and baryon asymmetry, The cosmological consequences of sphaleron transitions were considered for the minimal walking technicolor (WTC) model, which provides composite Higgs boson solution for the problem of Higgs boson mass divergence in the Standard model. The realisation of multi-component dark atom scenario is possible because the electric charges of new fermions are not fixed and several types of stable multiple charged states are possible. In particular cases the upper limits for the masses of techniparticles could be found, at which dark atom interpretation of dark matter is possible. These limits challenge search for multiple charged stable particles at the LHC.

hep-ph↗

arXiv2022

Evolution and Possible Forms of Primordial Antimatter and Dark Matter celestial objects

The structure and evolution of Primordial Antimatter domains and Dark matter objects are analysed. Relativistic low-density antimatter domains are described. The Relativistic FRW perfect-fluid solution is found for the characterization of i) ultra-high density antimatter domains, ii) high-density antimatter domains, and iii) dense anti-matter domains. The possible sub-domains structures is analyzed. The structures evolved to the time of galaxy formation are outlined. Comparison is given with other primordial celestial objects. The features of antistars are outlined. In the case of WIMP dark matter clumps, the mechanisms of their survival to the present time are discussed. The cosmological features of neutrino clumping due to fifth force are examined.

gr-qc↗

arXiv2021

Researching of magnetic cutoff for local sources of charged particles in the halo of the Galaxy

Models of highly inhomogeneous baryosynthesis of the baryonic asymmetric Universe allow for the existence of macroscopic domains of antimatter, which could evolve in a globular cluster of antimatter stars in our Galaxy. We assume the symmetry of the evolution of a globular cluster of stars and antistars based on the symmetry of the properties of matter and antimatter. Such object can be a source of a fraction of antihelium nuclei in galactic cosmic rays. It makes possible to predict the expected fluxes of cosmic antinuclei with use of known properties of matter star globular clusters We have estimated the lower cutoff energy for the penetration of antinuclei from the antimatter globular cluster, situated in halo, into the galactic disk based on the simulation of particle motion in the large-scale structure of magnetic fields in the Galaxy. We have estimated the magnitude of the magnetic cutoff for the globular cluster M4.

astro-ph.HE↗

arXiv2021

Statistical analyses of antimatter domains, created by nonhomogeneous baryosynthesis in a baryon asymmetrical Universe

Within the framework of scenarios of nonhomogeneous baryosynthesis, the formation of macroscopic antimatter domains is predicted in a matter-antimatter asymmetrical Universe. The properties of antimatter within the domains are outlined; the matter-antimatter boundary interactions are studied. The correlation functions for two astrophysical objects are calculated. The theoretical expression in the limiting process of the two-points correlation function of an astrophysical object and an antibaryon is derived.

physics.gen-ph↗

arXiv2021

Numerical simulation of Bohr-like and Thomson-like dark atoms with nuclei

The puzzles of direct dark matter searches can be solved in the scenario of dark atoms, which bind hypothetical, stable, lepton-like particles with charge $-2n$, where $n$ is any natural number, with $n$ nuclei of primordial helium. Avoid experimental discovery because they form with primary helium neutral atom-like states $OHe$ ($X~-$ helium), called "dark" atoms. The proposed solution to this problem involves rigorous proof of the existence of a low-energy bound state in the dark atom interaction with nuclei. It implies self-consistent account for nuclear attraction and Coulomb repulsion in such an interaction. We approach the solution of this problem by numerical modeling to reveal the essence of the processes of dark atom interaction with nuclei. We start with the classical three-body problem, to which the effects of quantum physics are added. The numerical model of the dark atom interaction was developed for $O^{--}$ having a charge of $-2$, bound with He in Bohr-like $OHe$ dark atom and for $-2n$ charged $X$ bound with $n$ $α$-particle nucleus in the Thomson-like atom $XHe$. The development of our approach should lead to the solution of the puzzles of direct dark matter searches in the framework of dark atom hypothesis.

hep-ph↗

arXiv2021

Production and evaporation of micro black holes as a link between mirror universes

It is shown that the equalization of temperatures between our and mirror sectors occurs during one Hubble time due to microscopic black hole production and evaporation in particle collisions if the temperature of the Universe is near the multidimensional Plank mass. This effect excludes the multidimensional Planck masses smaller than the reheating temperature of the Universe ($\sim10^{13}$ GeV) in the mirror matter models, because the primordial nucleosynthesis theory requires that the temperature of the mirror world should be lower than ours. In particular, the birth of microscopic black holes in the LHC is impossible if the dark matter of our Universe is represented by baryons of mirror matter. It excludes some of the possible coexisting options in particle physics and cosmology. Multidimensional models with flat additional dimensions are already strongly constrained in maximum temperature due to the effect of Kaluza-Klein mode (KK-mode) overproduction. In these models, the reheating temperature should be significantly less than the multidimensional Planck mass, so our restrictions in this case are not paramount. The new constraints play a role in multidimensional models in which the spectrum of KK-modes does not lead to their overproduction in the early Universe, for example, in theories with hyperbolic additional space.

astro-ph.CO↗

arXiv2020

Anihelium flux from antimatter globular cluster

Macroscopic cosmic antimatter objects are predicted in baryonasymmetrical Universe in the models of strongly nonhomogeneousbaryosynthesis. We test the hypothesis of the existence of an oldglobular cluster of anti-stars in the galactic halo by evaluating theflux of helium anti-nuclei in galactic cosmic rays. Due to the symme-try of matter and antimatter we assume that the antimatter clusterevolves in a similar way as a matter cluster. The energy density ofantiparticles in galactic cosmic rays from antimatter globular clusteris estimated. We propose a method for the propagation of a fluxof antinuclei in a galactic magnetic field from the globular cluster ofantistars in the Galaxy.

astro-ph.HE↗

arXiv2020

Numerical simulation of dark atom interaction with nuclei

The old and still not solved problem of dark atom solution for the puzzles of direct dark matter searches is related with rigorous prove of the existence of a low energy bound state in the dark atom interaction with nuclei. Such prove must involve a self-consistent account of the nuclear attraction and Coulomb repulsion in such interaction. In the lack of usual small parameters of atomic physics like smallness of electromagnetic coupling of the electronic shell or smallness of the size of nucleus as compared with the radius of the Bohr orbit the rigorous study of this problem inevitably implies numerical simulation of dark atom interaction with nuclei. Our approach to such simulations of $OHe-$nucleus interaction involves multi-step approximation to the realistic picture by continuous addition to the initially classical picture of three point-like body problem essential quantum mechanical features.

hep-ph↗

arXiv2019

A charming ICECUBE discover?

Last two years high energy neutrino data are studied. The two recent tau neutrino double bang candidate are discussed within their detectability, noise and expected rate. The neutrino flavor distribution mainly favoring equal electron and muon presence, is reminded. The angular distribution of highest muon neutrino tracks is analyzed. Their horizontal strong anisotropy and their remarkable up-down asymmetry, with the absence of clustering, is noticed. The main persistent missing of astrophysical X,gamma sources (as GRB and AGN flaring source) and all the above signatures led us to suggest a dominance of prompt charmed (atmospheric) events able to pollute, to smear and to hide any minor astronomical presence.

astro-ph.HE↗