Over the past five decades, methods of quantum field theory (QFT) have been fruitfully applied to a broad class of problems in classical physics — including phase transitions, chemical reaction kinetics, percolation, interfacial growth, fully developed turbulence, magnetohydrodynamics, and related phenomena — substantially advancing our understanding of complex stochastic systems and...
The talk will briefly cover the history of the emergence of the AdS/CFT correspondence (also called gauge-gravity or holographic duality) in string theory, as well as the subsequent application of the emerged ideas to the description of the phenomenology of non-perturbative strong interactions.
We investigate critical behavior near first-order phase transitions in QCD using gauge/gravity duality. A key focus is the selection of holographic models that best predict the locations of these transitions, including via modern machine learning methods. We also present new results on anisotropic holographic QCD, highlighting the non-trivial behavior of key equation-of-state parameters under...
The interplay of rotation, external magnetic fields, and quantum fields has become an active topic at the interface of quantum field theory, condensed matter, and high-energy physics. In this contribution, we study the formation of scalar condensates in a rotating frame and, in particular, the emergence of vortex solutions in a charged scalar field. Our analysis is motivated both by...
Magnetic skyrmions at the scale of tens of nanometers are actively discussed in the last decade. These topological objects are experimentally observed as skyrmion crystals (SkX) in a tightly packed triangular configuration. The main focus of experimental investigations and numerical modeling nowadays shifts to the preparation and manipulation of individual skyrmions, aiming to use them ...
Effective field theory of composite higher-spin particles is a formidable subject, where preserving the physical number of degrees of freedom in a Lorentz-invariant and parity-even way requires a host of auxiliary fields. They can be chosen to have a rich gauge-symmetry structure, but introducing consistent interactions in such approaches used to be a highly non-trivial task, with Lagrangians...
Magnetic skyrmions are topologically nontrivial whirls of local magnetization, that can arrange into regular lattices, co-called skyrmion crystals (SkX). Dzyaloshinskii-Moriya interaction (DMI) is one of SkX stabilization mechanisms. There is a wide region on a phase diagram of a thin ferromagnetic film with DMI in a presence of an external magnetic field where SkX is a ground state of the...
We prove that the supersymmetrcic Wess-Zumino model is internally incosistent as a local quantum field theory model.
The interaction model of two electrons in the edge states of a two-dimensional topological insulator is investigated. Both solutions of the Schr\"odinger equation and solutions of the Bethe-Salpeter equation at different values of the Fermi energy are considered. It is shown that for the Bethe-Salpeter equation, which takes into account the existence of the Fermi surface, there is a discrete...
Inspired by quantum-mechanical Landau method, we propose a new perturbatively exact relation between scattering amplitudes in bosonic theories and vacuum-to-vacuum transition amplitudes in the same theories with vanishingly weak sources on singular backgrounds. We argue that the new relation automatically resums the powers of g*n in perturbative amplitudes of n quanta production, where g is a...
We explore superfluidity in $SU(N)$ Fermi gases using the functional renormalization group. Going beyond mean-field we track the flow of the effective action and resolve thermodynamics near the transition. Our study uncovers a fluctuation-induced first-order superfluid transition for $N \geq 4$, absent at mean-field level. We quantify the critical temperature and the discontinuities in the...
In this talk (based on arXiv 2507.18746 and 2507.22999) I will show that in a massive scalar theory on a finite cylinder, operator local perturbations(quenches) drive dynamics whose time-resolved two-point functions exhibit spacing-ratio statistics along with other measures showing clear random-matrix behaviour. Extending to holography, I construct confining deformations by capping off AdS...
In this work, we employ a field-theoretic renormalization group approach to study a paradigmatic model of directed percolation. We focus on the perturbative calculation of the equation of state, extending the analysis to the three-loop order in the expansion parameter $\varepsilon = 4-d$. The main aims of this study are to provide an update on this ongoing work and to present the numerical...
In this talk, I represent a scenario where the nonzero curvature extension of the field space for the charged leptons induces a peculiar force that leads to a simple mechanism for generating the charged lepton flavor violation (CLFV). This novel force corrects the electromagnetic vertex, leading to an effective coupling which is flavor off-diagonal at tree level. Consequently, it yields the...
We consider the $f f \rightarrow f f$ scattering amplitudes for the a massless four-fermion interaction model in four dimensions. At first we take the simplest version with the scalar current-current interaction. The loop corrections up to the three-loop level are calculated within the spinor-helicity formalism using the Weyl spinors. We find out that there are two independent spinor...
In this talk, I present a bottom-up holographic model dual to a strongly coupled field theory which incorporates the spontaneous breaking of an approximate global symmetry yielding the SO(5)/SO(4) coset important for minimal composite-Higgs models. The gravity solution is smooth, mimicking confinement on the field theory side. A set of boundary terms are added to the gravity, introducing...
We focus on the study of RG flows of conformal field theories that are holographically dual to Poincare domain wall solutions in $D=3$, $N=(2,0)$ gauged supergravity coupled to a sigma model with target spaces $S^2$ or $\mathbb{H}^2$. This theory is truncated to a subsector where the vector field and phase of the scalar field vanish and we consider dynamics of the remaining real scalar field....
We consider different types of reducibility of a matrix $n\times n$ intertwining operator and reveal criterion for regular reducibility. It is shown that in contrast to the scalar case $n = 1$ there are for any $n\geqslant 2$ regularly absolutely irreducible matrix intertwining operators of any order $N\geqslant 2$, i.e. operators which cannot be factorized into a product of a matrix...
The talk is devoted to the three-loop renormalization of the effective action for a two-dimensional pricipal chiral field model using the background field method and a cutoff regularization in the coordinate representation. The coefficients of the renormalization constant and the necessary auxiliary vertices are found. Asymptotic expansions for all three-loop diagrams and their dependence on...
In experimental science, many phenomena remain beyond a self-consistent theoretical description. A prominent example is provided by the strong interaction: Yang–Mills theory, which models it, requires solving highly nonlinear equations that are still intractable in general. Several decades ago, however, advances in string theory led to the holographic correspondence (AdS/CFT). By analyzing the...
We study a stochastic version of magnetohydrodynamics (MHD) formulated as the generalized A-model of a passively advected vector field with full back-reaction on the flow. The model includes parity breaking via a helicity parameter ρ and a continuous interaction parameter A that interpolates between important physical limits (A = 1 for MHD, A = 0 for passive vector advection). Using the...
Attributing thermodynamic properties to the Bunch-Davies state in static patch of de Sitter space and setting the corresponding equations of state, we demonstrate that, for pure gravity, the bulk entropy computed on-shell as a volume integral in de Sitter space coincides with the Wald entropy (area law) in any spacetime dimension and for any theory of f(R) gravity. We extend this result to the...
We performed a two-loop field-theoretic analysis of incompressible, helical magnetohydrodynamics (MHD) in a fully developed, statistically stationary turbulent state. A distinctive feature of turbulence in helical media is the emergence, within the loop expansion of the magnetic response function, of an infrared-relevant, mass-like contribution. Physically, this term corresponds to a...
The method is developed that adjusts the Faddeev-Popov factorization procedure for the quantization of generic reducible gauge theories with linearly dependent generators. Using this method a covariant quantization of recently proposed totally antisymmetric tensor spinor field theory in AdS space is carried out and the corresponding effective action is obtained in terms of special Dirac-type...
Standard Model is neither phenomenologically nor theoretically complete theory of fundamental physics. Many of its motivated extensions predict phase transitions in the early Universe, which, if source the gravitational wave production, may be probed with present and future instruments aimed at measurement of gravitational waves. This is a unique way to trace the history of the early Universe...
In this talk we understand by "dimensional transmutation" a situation when, in a certain field theoretic model, a certain canonically dimensionless parameter (like a coupling constant) acquires a nontrival critical dimension in the infrared asymptotic range of scales (long times, large distances). This situation is not unfrequent and was encountered in stochastic magnetic hydrodynamics,...
The leptonic decays of heavy quarkonia are complementary observables to the semileptonic decays of heavy mesons and provide additional insight into the possible lepton flavor universality breaking. These decays are analyzed in the framework of the covariant confined quark model by using a novel approach for the description of the radially excited quarkonia states. It turns out that the...
The study of critical dynamics in the vicinity of the superfluid phase transition presents an unresolved problem: determining the power-law behavior of viscosity upon approaching the critical point. The corresponding dynamic critical exponent remains unknown. Within a phenomenological model, direct computations prove exceedingly complex; the renormalization procedure involves the mixing of...
A topological geon is an asymptotically (anti-)de Sitter or flat spacetime with topology $\mathbb{R}\times{}M$, where $M$ is the punctured projective space, $M=\mathbb{R}P^3\,\backslash\{p\}$, and the removed point $p$ corresponds to the spacelike infinity. The spacelike slice $M$ is conventionally obtained as the quotient $W/\mathbb{Z}_2$ of a symmetric wormhole $W$ by the isometric action of...
Hwa–Kardar "running' sandpile model was an attempt to construct a continuous stochastic equation (an effective coarse-grained large-scale description), the derivation of which is based solely on conservation laws, relevant symmetries and dimensionality considerations, in order to capture the hypothetical mechanism behind self-organized criticality, namely, transport in a driven diffusive...
The Brout-Englert-Higgs (BEH) boson mass evolution in the Standard Model is discussed. The quadratic self-energy divergence in addition to the logarithmic ones due to the renormalization of the scalar BEH boson mass causes the so-called Naturalness problem.
We study a novel variation of the large D limit in which s-wave sector is described by a 2D gravity nearly decoupled from other modes, but temperature remains finite. We discuss the quantum description of such system and it's thermal behavior
Employing the renormalization group method, we study the behavior of the explicitly anisotropic Hwa-Kardar sandpile model encompassed by an explicitly isotropic randomly moving medium. The motion of the medium is described by the stochastic Navier-Stokes equation with a random stirring force of a rather general form that includes, in particular, the overall shaking of the system and a...
In the report, the off-shell electromagnetic pion form factors in the Bethe-Salpeter formalism are considered. The separable kernel of the first rank quark-antiquark interaction is used to solve the equation analytically. The half-off-shell pion form factors and, which are related to each other by the Ward-Takahashi identity, are calculated. The obtained off-shell form factors as well as...
A black hole can evaporate through the mechanism proposed by Hawking. In the case of a Schwarzschild black hole, this leads to the temperature of the black hole increasing without bound as its mass decreases. However, if the black hole possesses multiple horizons, as in the case of regular black holes, the picture changes dramatically. In our work, we analyze the behavior of the Hawking...
The talk is devoted to the model of random walk on a fluctuating rough surface using the field-theoretic renormalization group (RG). The surface is modelled by the well-known Kardar-Parisi-Zhang (KPZ) stochastic equation while the random walk is described by the standard diffusion equation for a particle in a uniform gravitational field. In the RG approach, possible types of infrared (IR)...
The connection between Standard Model (SM) particles and light dark matter (DM) can be introduced via spin-0, spin-1, and spin-2 mediators. Moreover, in a mediator mass range from sub-MeV to sub-GeV, fixed-target facilities such as NA64e, LDMX, E137, NA64mu, and M3 can potentially probe such particles of the hidden sector via missing energy signatures that are described by the...
Coexistence of heavy particles and primordial black holes in early Universe can result in baryon asymmetry production. It requires C and CP symmetries violation of particles scattering on relativistic symmetric plasma. Generation mechanism is considered with including expansion effects. Several possible realizations can be considered with different resulting asymmetry and available parameters space.
We compute the vacuum energy of a scalar field rotating with angular velocity Ω on a disk of radius R and with Dirichlet boundary conditions. The rotation is introduced by a metric obtained by a transformation from a rest frame to rotating frame. To compute the vacuum energy, we use an imaginary frequency representation and the well-known uniform asymptotic expansion of the Bessel function....
Tricritical behavior in systems with an $n$-component order parameter $\varphi = \{\varphi_k, k = 1, \ldots, n\}$ is described by the action
\begin{equation}
S(\varphi) = \frac{1}{2}\partial_i\varphi_k\partial_i\varphi_k + \frac{\tau_0}{2} \varphi_k\varphi_k + \frac{\lambda_0}{4!} (\varphi_k\varphi_k)^2 + \frac{g_0}{6!} (\varphi_k\varphi_k)^3,
\end{equation}
where the coefficients...
In this talk, using the calculation of the dynamic critical exponent $z$ in the Model A in the four-loop approximation as an example, we will present the diagram reduction technique. This method allows for a substantial decrease in both the number of diagrams and divergent dynamic subgraphs, thereby facilitating subsequent parametric integration with Goncharov polylogarithms.
We perform numerical semiclassical calculations of the false vacuum decay probability for a scalar field in the Schwarzschild spacetime. The suppression $F$ of the decay probability $P \sim e^{-F}$ is given as a functional of a semiclassical solution. That solution is defined on a certain contour in complex time. We consider a model with potential $V(\phi) = \frac{1}{2}m^2 \phi^2 - \frac{1}{2}...
Sigma models constitute a fundamental class of field theories with wide-ranging applications in theoretical and mathematical physics. However, their analysis is often complicated by the nonlinearity of their Lagrangians. While traditional approaches, such as the background field method, offer partial insights, they face inherent limitations.
In this talk, I will present an alternative...
Models of black holes that differ from idealized vacuum and electrovacuum solutions of Einstein's equations often contain parameters whose physical interpretation is unclear. However, to propose a black hole model for experimental verification, we must clearly understand which parameters describe the black hole and what physical constraints can be imposed on each parameter. When considering...
We propose the explicit construction of fields in the orbifolds of products of $N=(2,2)$ minimal models with ADE invariants. It is shown that spectral flow twisting by the elements of admissible group $G_{\text{adm}}$, is consistent with the nondiagonal pairing of D and E type minimal models. We obtain the complete set of fields of the orbifold from the mutual locality and other requirements...
This talk presents the application of parametric integration with Goncharov polylogarithms to multiloop analytic calculations in models of critical dynamics. The technique has been successfully applied in various high-energy physics and static critical models. Its main requirement is linear reducibility of the integrals under evaluation. In dynamical models, linearly non-reducible integrals...
In this talk, we will explore the dynamics of entanglement entropy and entanglement islands within a two-sided Reissner-Nordström black hole placed in a cavity bounded by a reflecting wall. This setup alters the dynamics of entanglement entropy, causing it to saturate at a value that is potentially lower than the thermodynamic entropy of the black hole, which contradicts the Page curve...
The renormalization-group approach is used to investigate the possible IR behavior of a randomly walking particle in a random dynamic environment. The particle movement is modeled by the stochastic Fokker -- Planck equation. The dynamics of the environment are described by a random drift field $F_j$ with a pair correlator, which implies two limiting cases -- a "rapidly-changing" and...
Pseudoscalar particles called axions are promising candidates for dark matter constituents [1]. The hypothetical interaction of axions with leptons (e.g., electrons) produces an effective electron-electron interaction. When considering electrons in hexatomic molecules, e.g., RaOCH$_3$, such interaction via axion exchange is capable of violating the parity parity of molecular Hamiltonian. Thus,...
We present a new framework for evaluating multipoint one-loop parametric conformal integrals in arbitrary dimensions. Our approach, called reconstruction, is based on a diagrammatic algorithm which systematically builds a class of multivariate generalized hypergeometric series in terms of a convex polygon which is part of the Baxter lattice. The talk is based on joint work with K.B. Alkalaev.
The field-theoretic renormalization group (RG) method was used to study the behavior of a randomly walking particle on a rough surface. The surface was given by the conserved Kardar--Parisi--Zhang (CKPZ) stochastic equation, and the random walk was governed by the standard diffusion equation for a particle in a uniform gravitational field. The complete model was presented as a field-theoretic...
The holographic duality provides a powerful framework for understanding strongly interacting conformal field theories, and more generally, quantum field theories. The AdS/CFT correspondence, its prime and most concrete example, is largely based on the connection between the isometry group of the AdS spacetime and the conformal group, but is not exhausted by this.
The main statement of the...
Functional representations for the generating function of field-theoretic Green functions of the stochastic differential equation with multiplicative noise are constructed with the use of the stochastic integral of Itô. Differences in the functional representations due to interpretations of Itô and Stratonovich of the stochastic differential equation are pointed out.
The first version of the massive theory of gravity was introduced by Fierz and Pauli in 1939. In 1972 Boulware and Deser found ghosts in massive theories of gravity and physicists concluded that such theories hardly ever could be realizable in nature. Several years ago C. de Rham and her co-authors showed that there is an opportunity to create massive theories of gravity without ghosts (see,...
We investigate the possibility of explaining the observed effects usually attributed to the existence of dark matter through a transition from GR to a modified theory of gravity - embedding gravity. Since this theory can be reformulated as GR with additional fictitious matter of embedding gravity (FMEG), which moves independently of ordinary matter, we analyse solutions in which FMEG behaves...
One parameter family of exact solutions in General Relativity with a scalar field has been found using the Liouville metric. The scalar field potential has exponential form. The solution corresponding to the naked singularity provides smooth extension of the Friedmann Universe with accelerated expansion through the zero of the scale factor back in time. All geodesics are found explicitly....
We propose a dynamical mechanism of vacuum energy cancellation by a scalar field $\phi$ coupled to curvature scalar as $\beta R \phi^2 f(\phi)$ where $f(\phi)$ is a polynomial function of $\phi$. It is shown that the exponential expansion driven by vacuum energy is dynamically transformed into the standard cosmological evolution of a radiation-dominated universe.
We extend in a simple way the well-known low-energy theorem for an effective Higgs-like scalar-gluon-gluon coupling in QCD including arbitrary number of heavy quarks in addition to the light ones. The application of the extended low-energy theorem leads to a new result: an extraction of the four-loop effective Higgs-gluon-gluon coupling valid for extensions of the Standard Model with...
We list K-matrices for the general linear and orthosymplectic quantum supergroups with the simplest "symmetric" triangular decomposition. This classification is based on a theory of super-spherical coideal subalgebas in quantum supergroups associated with Z_2-graded Satake diagrams. This theory extends quantum symmetric pairs of Letzter-Kolb to the realm of quantum supergroups.
Features of deviation of circular trajectories in the central field in non-relativistic and relativistic cases are investigated. All potentials for which perturbed trajectories in the non-relativistic case are closed and asymptotically flat spherically symmetric metrics with closed perturbed orbits are found. It is shown that in the general theory of relativity there are metrics in which the...
For affine special superalgebra $\mathfrak{\hat{g}}(\Pi)$ defined by an arbitrary systems of simple roots $\Pi$ we define the affine super Yangian $Y_{\hbar}(\hat{g}(\Pi))$ as Hopf superalgebra which is a quantization of superbialgebra $\hat{g}(\Pi)[t]$ and describe super Yangian in terms of minimalistic system of generators. We consider Drinfeld presentation for $Y^D_{\hbar}(\hat{g}(\Pi))$...
New aspects of gauge-gravity relation
The relation between four-dimensional $SO(4)$ pure Yang-Mills theory
and the gravity is discussed. The functional integral for Yang-Mills theory is rewritten in terms of the gravity metric and Riemann tensors.
Its peculiar feature is the cosmological term added to the Einstein-Hilbert action. This relation is shown to also provide a simple way to...
In this talk, construction of the superfield action of the $N = (1, 0)$, $d = 6$ non-Abelian tensor multiplet based on the non-Abelian tensor hierarchies is discussed. The supersymmetric systems of tensors with non-Abelian gauge symmetries are considered to be necessary tools for low-energy effective description of multiple M5-branes, as well as superconformal theories in six dimensions. The...
Isometric embedding of a pseudo-Riemannian spacetime is a description of this spacetime as a surface in an ambient spacetime of higher dimension. This procedure has been used for more than a century in the examination of solutions of Einstein equations, since the embedding class (i.e. the minimal codimension of a surface in a flat ambient spacetime) is an invariant characteristic of a...
We study the formation of composite weekly bound particles with large transverse momentum by means of the coalescence mechanism in high-energy hadron collisions. We find the coalescence coefficient by calculating the corresponding Feynman diagrams near the kinematic boundary, taking into account the coherent nature of the process. In this approximation, we calculate the dependence of the...
The application of the Horndeski theory in late-time cosmology is strongly limited by the strict coincidence of the propagation speeds of gravitational and electromagnetic waves. This restriction assumes that a photon with minimal coupling is not modified even at scales at which General Relativity (GR) may need modification. We have shown that the four-dimensional Galileon, obtained as a...
We demonstrate that the limit density of eigenvalues of random matrices from Jacobi Unitary Ensemble (JUE) coincides with the transition probability for the limit shape of random Young diagrams with respect to the measure obtained from skew Howe duality. We discuss conjectural connection of asymptotics of correlation functions in these random ensembles.
The Regge-Gribov model describing interacting pomerons and odderons is proposed with triple reggeon vertices taking into account the negative signature of the odderon. Its simplified version with zero transverse dimensions is first considered. No phase transition occurs in this case at the intercept crossing unity. This simplified mosel is studied without more approximations by numerical...
We study non-topological bright solitons in two-dimensional conformal field theory. Our analysis shows that these solitons exhibit only zero modes, with no vibrational or decay excitations. This behavior is explained by examining a relativistic extension of the model, where conformal symmetry is weakly violated and decay modes appear. Thus, the restoration of conformal symmetry ensures the...
The hidden-charm strong decays of the exotic charmonium-like state $Y(4230)$, recently reported by the BESIII Collaboration, has been investigated in the framework of the covariant confined quark model. The state $Y$ has been interpreted as a four-quark state with molecular-type interpolating current. We evaluate the hidden-charm decay width of $Y$ into a vector and a scalar, with the latter...
The importance of the realativistic corrections will be demonstrated for solitons in (2+1)-dimensional scalar theory with the conformal symmetry restoration in the non-relativistic limit. The conformal symmetry restoration affects the properties of solitons, such as their integral characteristics and stability.
We discuss latest results on Kaluza-Klein compactifications of Horndeski-type theories (beyond Horndeski and DHOST included). We show the subclass of such theories that obeys principal phenomenological constraints for dark energy models.
We study the possibility of resonant production of millicharged scalar particles by a timelike ($k^2>0$) electromagnetic wave, which can be experimentally obtained in plasma or in a medium with refractive index $n < 1$ (metamaterial). We show that the classical Klein-Gordon equation for the millicharged scalar field reduces to the Mathieu equation, which has exponentially growing solutions in ...
At the beginning of the 21st century, a new phase of strongly interacting matter, known as the quark-gluon plasma (QGP), was established [1]. To study QGP formation in heavy-ion collisions, the solution of system of relativistic hydrodynamics equations with a specific equation of state (EoS) is typically employed. In light of difficulties for non-zero baryonic potentials within Lattice QCD,...
We investigate the possibility of addressing the cosmological constant problem through a self-tuning mechanism within the framework of beyond Horndeski theory. In particular, we propose a cosmological scenario in which self-tuning operates during inflation but switches off prior to reheating, while leaving behind the correct dark energy density. Furthermore, we explore the use of self-tuning...
We calculate the nonlocal gravitational effective action for scalar field non-minimally coupled to gravity up to second order in curvature expansion at finite temperature and apply the result obtained to anomaly driven inflation scenario.
We consider a class of two-dimensional dilaton gravity models with linear dilaton vacuum including Callan-Giddings-Harvey-Strominger (CGHS) model as the special case. General thermodynamic properties of black holes in such models are evaluated. We focus on the CGHS model and its modification with regular black holes as empty-space solutions characterized by ever-present finite curvature. We...
The talk will review the reconstruction project of the Troitsk Meson Factory (TiMoFey, INR RAS). One of the possible directions of its work is the search for light feebly interacting particles. For this purpose, it is planned to use the proton beams with kinetic energies of 423 MeV and 1300 MeV hitting a graphite target.
The talk will consider the model of the leptophobic B-boson...
In a recent series of papers, e.g. (Das, Krishnan, Kumar and Kundu, 2023), (Das, Garg, Krishnan and Kundu, 2023), (Das and Kundu, 2024), it was noted that the spectral form factor, defined for massless scalar field normal modes on the BTZ black hole background with a stretched horizon, exhibits the dip-ramp-plateau structure. This is exactly the same structure of the spectral form factor that...
The problem of essential scheme-dependence of the effects of the EW perturbative EW corrections to the ratio pole-running top quark mass is analysed in details. It is mentioned that the similar features may manifest itself in the cases of pole-running b- and c-quark masses. The less importance in these circumstances roles of the effects of higher order QCD corrections to the ratios of...
The approach proposed by K. Symanzik for constructing quantum field models in inhomogeneous space-time is proposed to be used to describe the interaction of the basic fields of the theory of elementary particles with a continuous material medium. The main principles of constructing such models are formulated and examples of their application are given for studying the interaction of quantum...
Deviation of the cross section for the nuclear reaction X(a, b)Y from the Gamow formula due to an interaction additional to the Coulomb one in the entrance channel has been analyzed[1]. It is shown that the reaction cross section has an oscillating structure at low energies. If the maximum of the first oscillation is close to the threshold of the channel a+X, it has a resonance behavior[2]. To...
Form of axion state in the DFSZ-I and DFSZ-II models are re-examined by diagonalizing the mass mixing matrix of $CP$-odd sector as well as applying $PQ$ mechanism to determine $PQ$ charges of particles that are used in general form of axion. In these models, $PQ$ charge of the singlet scalar is the only one parameter for $U(1)_{PQ}$ symmetry. Anomaly couplings of axion and axion-photon-photon...
Termwise integration of the asymptotic DeWitt expansion yields kernel expansions for a wide class of operator functions. These expansions involve the well-known HaMiDeW coefficients (this property is precisely the off-diagonal generalization of "functoriality") multiplied by some functions representable by Mellin-Barnes (MB) integrals. Off-diagonality, together with the use of the properties...
The dependence of theoretical predictions for high-energy QED processes on factorization scale and scheme choices is studied. Examples for particular processes of Bhabha scattering, muon decay and electron-positron annihilation are presented.
The nonrelativistic quantum electrodynamics (NRQED) formalism to the nonrelativistic bound state problem is developed. The next-to-leading order corrections ($mα^6$) to nonrelativistic binding energies are derived. The infinities which appear in the bound-state formalism at this order are discussed. We consider how higher-order corrections in the fine structure constant α, including...
We derive the general rules of functional integration in the theories of Schwarzian type,
thus completing the elaboration of Schwarzian functional integrals calculus.
The Schwarzian functional integrals has played a role in many areas of quantum physics.
In recent decades it has appeared in the quantum mechanical model of Majorana fermions with a random interaction (Sachdev-Ye-Kitaev...
We present the harmonic superspace formulation of $\mathcal{N}=2$ hypermultiplet in AdS$_4$ background, starting from the proper realization of $4D$, $\mathcal{N}=2$ superconformal group $SU(2,2|2)$ on the analytic subspace coordinates. The key observation is that $\mathcal{N}=2$ $AdS_4$ supergroup $OSp(2|4)$ can be embedded as a subgroup in the superconformal group through introducing a...
In this talk, we will discuss the phenomenon of electron-positron pair production in strong electromagnetic fields and first- and second-order radiative processes. Main focus will be placed on the recent theoretical developments concerning a nonperturbative description of the above effects. We will briefly discuss modern theoretical approaches in quantum electrodynamics with unstable vacuum,...
We calculate the chiral effective superpotential in $4D$ $\mathcal{N}=1$ $SU(N)$ super Yang-Mills theory coupled to chiral matter in one- and two-loop approximations. It is found that the one-loop contribution to the chiral effective potential is always finite and is expressed in terms of a specific triangle integral. The two-loop contributions generated by purely chiral vertices turned out...
Using the harmonic superspace approach, we perform a comprehensive study of the structure of divergences in the higher-derivative $6D, {\cal N}=(1,0)$ supersymmetric Yang--Mills theory coupled to the hypermultiplet in the adjoint representation. The effective action is constructed in the framework of the superfield background field method with the help of $ {\cal N}=(1,0)$ supersymmetric...
The probability amplitudes of a photon emission from the vacuum accompanied by a created electron-positron pair or from a single-electron (positron) state in the presence of a constant electric field were considered earlier by Nikishov [Zh. Eksp. Teor. Fiz. 59, 1262 (1970)]. However, these amplitudes present a satisfactory description of the phenomenon of the emission in the case of not so...
The search for $\mathcal{T}$- and $\mathcal{P}$-violating interactions, where $\mathcal{T}$ denotes time-reversal symmetry, and $\mathcal{P}$ denotes spatial parity, has been a central focus in fundamental physics for the past 75 years. Despite substantial progress in improving experimental limits on these interactions, theoretical predictions, even within the Standard Model (SM), remain...
Based on numerical simulation of two-color QCD in lattice regularization, correlations between fluctuations of the quark condensate, the net-quark number density, and the Polyakov loop are estimated.
For the pion mass $\sim 700$~MeV, there is a significant correlation at temperatures of $200-320$~MeV, which indicates a connection between the dynamics of chiral symmetry restoration and...
The main topic of my talk is the correspondence between the gravitational Wilson line networks and Witten diagrams for massive scalar fields in AdS$_2$. I will show that Witten diagram can be expanded into a sum of gravitational Wilson line networks, where each term in the sum has distinct boundary behaviour. This expansion is similar to the conformal block expansion of conformal correlators...
Using first-principle numerical simulations, we find a new spatially inhomogeneous phase in rotating gluon plasma. This mixed phase simultaneously contains regions of both confining and deconfining states in thermal equilibrium. The location of the spatial transition between the two phases is determined by the local critical temperature. We measure the local critical temperature as a function...
The Quantum Field Theory methods, related to the M-theory structures, are playing exceptional role in the modern science. They are commonly united in the general Gauge/Gravity correspondence. During the recent years of the related techniques' development, plenty of the general effects and their common features were recovered for the quantum field theories in the critical point, - conformal...
In this work, we study the effective potential for non-renormalizable general and SO(N) symmetric scalar theories in curved space-time. We discuss a method for finding all-loop corrections in the leading logarithmic approximation, which incorporates the non-minimal coupling with gravity within the linear curvature approximation.
Using the Bogoliubov-Parasyuk theorem, we derive recurrence...
We investigate the properties of SU(3) gluon plasma at high temperature under acceleration using lattice simulations in Rindler spacetime. Our results reveal a spatial crossover transition from confinement to deconfinement opposite to the direction of acceleration, consistent with the Tolman-Ehrenfest (TE) law. Using this law, we renormalize the Polyakov loop in Rindler space. Additionally, we...
A bottom-up soft-wall holographic model is used to capture the non-perturbative dynamics of a composite Higgs sector undergoing a first-order phase transition. Employing a controlled perturbative expansion in the dual 5D theory, we obtain estimations of bubble nucleation rates and other parameters of phase transition. This semi-analytic approach yields a prediction for the resulting...
The report presents a generalization of the Green’s function method for the scattering problem, allowing for the mixing of electromagnetic polarizations upon reflection from planar interfaces with Chern–Simons (CS) boundary layers. The developed approach makes it possible to systematically derive the Casimir-Polder potential for systems with such boundaries.
The formula for the...
In this report we present the results of our study of rotating gluodynamics. In particular, we carry out lattice calculation of total angular momentum of rotating gluodynamics for various temperatures and angular velocities within local thermalization approximation. In this approximation, instead of simulating the full action, we use the action with the coefficients being fixed at some...
Effective potential in an arbitrary non-renormalizable scalar field model in subleading order is calculated. Based on BPHZ-renormalization and Bogoliubov-Parasiuk theorem it is found formalism to construct generalization of usual renormalization group equations. Application of this formalism leads to efficient way of calculation quantum contribution to effective potential whether...
Certain observed phenomena cannot be explained within the framework of General Relativity (GR) without the introduction of dark matter. One may attempt to avoid its introduction by moving to a modified theory of gravity—embedding gravity. Within this framework, a 4-dimensional spacetime is considered as a surface embedded in a 10-dimensional flat Minkowski space.
It turns out that it is...
In this work, we present an overview of Dirac's classical approach for obtaining the Hamiltonian formulation of gauge systems, with a particular focus on systems where "gauge hits twice", resulting in the simultaneous appearance of two first-class Hamiltonian constraints for every given pure gauge mode. The validity of the Dirac conjecture, which states that all first-class constraints serve...
The work is focused on analyzing $J/\psi \rightarrow 4\pi_0 + \gamma$ decay reaction via partial-wave analysis on the Bes III experiment data. This analysis is relevant for the particle research due to the expected production of exotic resonances, in particular, glueballs. Glueballs are an important prediction of QCD, hypothetical particles consisting purely of gluons. The work covers all...
Studies of the phase diagram of strongly interacting matter created in nuclear collisions are typically carried out using event-by-event fluctuations. The strongly intensive quantities form a family of promising observables that are free from trivial volume fluctuations. In the case of multiplicity fluctuations over separate rapidity intervals, the behavior of the corresponding strongly...
