New continuous spin superparticle models in 4D, N=1 flat and AdS_4 superspace are presented. The models are described by 4D, N=1 superspace coordinates together with commuting Weyl spinor additional variables, which are inherent ingredients of continuous spin models. A canonical formulation, specific local fermionic kappa-symmetry, and a compete system of bosonic and fermionic constraints are...
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...
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 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....
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...
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 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....
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...
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...
We study a toy-model of continuous infinite expansion of space-time with the flat start. We use as the gravitational background a conformaly flat metric with growing factor in conformal time. We aim to clarify some properties of quantum fields in such a gravitational background. In particular, we calculate one-loop corrections to the Keldysh propagator to verify the fact of secular growth of...
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.
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.
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...
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 finite formulation of QFT, which is based on the system of the differential equations is discussed. This system of equations was previously formulated on the bare language; we show, that these equations can be re-formulated in a fully renormalized language. Next, it is demonstrated that under the certain conditions, the class of such finite renormalization prescriptions is equivalent to...
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...
General formula for symmetry factors (S-factor) of Feynman diagrams containing fields with high spins is derived. We prove that symmetry factors of Feynman diagrams of well-known theories do not depend on spins of fields. In contributions to S-factors, self-conjugate fields and non self-conjugate fields play the same roles as real scalar fields and complex scalar fields, respectively. Thus,...
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...
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...
We continue the development of a position space approach to equations for Feynman multi-loop integrals. The key idea of the approach is that unintegrated products of Greens functions in position space are still loop integral in momentum space. The natural place to start are the famous banana diagrams, which we explore in this paper. In position space, these are just products of n propagators....
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...
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...
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...
