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...
R-operation and locality of QFT guarantees locality of the counterterms in coordinate space or at most polinomiality in momentum space. This leads to relations between the counterterms in subsequent orders of perturbation theory. In its turn these relations allow one to get the recurrent relations which can be promoted to RG equations for the leading, subleading, etc logarithms. Remarkably...
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...
Due to the lack of statistically reliable manifestations of effects beyond the Standard Model (SM) in LHC experiments, special attention is paid to the construction of an effective field theory in which deviations from the SM are parameterized by a set of gauge-invariant local operators with dimensions greater than four. The main features and current status of this approach, called the...
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,...
Harmonic ${\cal N}=2$ superspace was discovered in 1984 as the powerful unique tool of the geometric superfield off-shell description of ${\cal N}=2, 4D$ supersymmetric field theories with the maximal spins 1, 2, and 1/2 (${\cal N}=2$ Yang-Mills theories, supergravity and matter hypermultiplets). Later on, harmonic superspace methods were successfully applied to set up the previously unknown...
In our previous works, we used the graph-building operator technique, together with the connection to conformal quantum mechanics, to obtain an all-loop result for the conformal ladde and zig-zag four-point diagrams in arbitrary dimensions. While our expression for ladder diagrams was fully analytical and valid in any dimension, it was formulated in terms of Gegenbauer polynomials, so despite...
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...
We solve the classical and quantum problems for the 1D sigma model with target space the flag manifold U(3)/U(1)^3, equipped with the most general invariant metric. In particular, we explicitly describe all geodesics in terms of elliptic functions and demonstrate that the spectrum of the Laplace-Beltrami operator may be found by solving polynomial (Bethe) equations. The main technical tool...
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.
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...
The current status of testing QED in strong and supercritical Coulomb fields is considered. Special attention is paid to tests of QED in the supercritical Coulomb field. It is known that in slow collisions of two bare nuclei with the total charge number exceeding the critical value, $Z_1+Z_2 > Z_c =173$, the initially neutral vacuum can spontaneously decay into a charged vacuum and two...
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...
