arXiv subjects

Evgeny Skvortsov

Publications and source records attributed to Evgeny Skvortsov.

At least 19 recordsLinked to original sources

arXiv2026

A simple construction of Heat Kernels and conformal anomalies via Fedosov deformation quantization

We propose a new approach to the systematic computation of the heat-kernel expansion and, in particular, of conformal anomalies, based on Fedosov deformation quantization. The approach is fully covariant, applies to differential operators of arbitrary order, is amenable to efficient implementation, and yields closed-form expressions. As applications, we compute conformal anomalies in four, six, and eight dimensions, the last being a new result.

hep-th↗

arXiv2026

Spinor-helicity formalism for continuous-spin particles

We propose a new formulation of continuous-spin particles (CSP) with the help of a single two-component spinor to build asymptotic states. This formulation allows to write down amplitudes in a straightforward way, similar to the massless spinor-helicity approach. The helicity states naturally emerge upon decomposing into components of a fixed homogeneity degree. We show that CSP amplitudes can be understood as the infinite-spin limit of amplitudes of massive particles and, similarly to the scattering of black holes, a certain universal factor exponentiates. In analogy with the recent discovery of collinear amplitudes in self-dual theories, we find nontrivial CSP collinear amplitudes where the collinear fractions are constrained by the dimensionful parameter characterising the various continuous-spin particles.

hep-th↗

arXiv2026

Dirichlet, Neumann, Mixed and self-dual holography: (self-dual) Yang--Mills theory II

We consider Yang--Mills, Chalmers--Siegel and self-dual Yang--Mills (SDYM) theories within AdS/CFT correspondence. Bulk-to-bulk and boundary-to-bulk propagators are derived in various gauges and for Dirichlet, Neumann, mixed and self-dual boundary conditions. Three- and four-point holographic correlators are computed in the three theories to establish the relation between the observables thereof. This is a companion paper to [arXiv:2602.21658].

hep-th↗

arXiv2026

Diamonds Are Forever: Stabilization Semantics for Unrestricted Aggregation and Recursion in Logica

Logica is an open-source logic programming language that compiles to SQL and runs on DuckDB, SQLite, PostgreSQL, and BigQuery. Unlike classic Datalog, it freely combines recursion and aggregation, concisely expressing algorithms from shortest paths to PageRank. This expressiveness raises semantic challenges: aggregates update by replacement rather than accumulation, evaluation depends on rule scheduling, and programs may converge to meaningful results without reaching a fixpoint, placing them outside traditional fixpoint semantics. We address this with Defendant-Opponent (DO) semantics, a stabilization-based framework for nonmonotonic logic programs. Evaluation is modeled as a rewrite system over derivation states, and a ground atom is true if, from every reachable state, some continuation makes the atom persist in all further derivations. This admits two equivalent characterizations: game-theoretically, truth is what a Defendant can defend against any Opponent in a three-turn game; and modally, truth corresponds to []<>[]t in the derivation graph viewed as a Kripke structure, placing nonmonotonic reasoning within S4. DO semantics coincides with least fixpoint semantics for positive Datalog and is compatible with both Well-Founded and Stable Model Semantics. For programs that converge without a fixpoint, {\omega}-limit interpretations give rigorous meaning to iterative computations such as PageRank.

cs.LO↗

arXiv2026

Self-dual holography: four-point AdS/CFT correlators in higher-spin gravity

Self-dual theories, being UV-finite, should have their own AdS/CFT dualities. Higher-spin extensions of self-dual theories are attractive to simplify the CFT duals. The maximal self-dual theory is Chiral higher-spin gravity, which should be dual to a subsector of Chern--Simons matter theories. As a step toward establishing self-dual holography, we develop the Fefferman--Graham expansion and holographic dictionary for arbitrary spin self-dual theories. As an application, we derive bulk-to-bulk propagators and compute three- and four-point AdS/CFT correlators in a contraction of Chiral higher-spin gravity, which is a higher-spin extension of self-dual Yang--Mills theory.

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arXiv2026

Amplitudes in self-dual (higher-spin) theories

Self-dual theories are powerful toy models of their completions. It was shown recently that there are infinitely many SD-theories once massless higher-spin fields are allowed. The maximal SD-theory is chiral higher-spin gravity. Following the recent [arxiv:2602.12176] we show that all SD-theories, including those with massless higher-spin fields, have nontrivial tree-level amplitudes in Kleinian signature or complex Minkowski kinematics. Within celestial holography, the nontriviality of amplitudes in chiral higher-spin gravity provides the missing ingredient needed to complete the celestial analogue of the vector-model/higher-spin AdS/CFT duality.

hep-th↗

arXiv2026

Logical Robots: Declarative Multi-Agent Programming in Logica

We present Logical Robots, an interactive multi-agent simulation platform where autonomous robot behavior is specified declaratively in the logic programming language Logica. Robot behavior is defined by logical predicates that map observations from simulated radar arrays and shared memory to desired motor outputs. This approach allows low-level reactive control and high-level planning to coexist within a single programming environment, providing a coherent framework for exploring multi-agent robot behavior.

cs.MA↗

arXiv2026

Dirichlet, Neumann, Mixed and self-dual holography: (self-dual) Yang-Mills theory

Motivated by applications of self-dual theories to the AdS/CFT correspondence, we study self-dual Yang-Mills theory (SDYM) and its relation to Yang-Mills theory and to Chalmers-Siegel theory with Dirichlet, Neumann, and mixed boundary conditions. A Fefferman-Graham analysis of SDYM is performed to identify its boundary CFT data. We make a proposal for self-dual holography that defines $3d$ ``self-dual CFTs''. The bulk-to-bulk and boundary-to-bulk propagators for SDYM and for Yang-Mills/Chalmers-Siegel theory with mixed boundary conditions are derived in Feynman and axial gauges. Three- and four-point functions are computed in the spinor-helicity formalism, and the relations among the results in the various theories are clarified. The flat limit and the gauge-(in)dependence of the results are analyzed.

hep-th↗

arXiv2026

Multisymplectic AKSZ sigma models

The Alexandrov-Kontsevich-Schwarz-Zaboronsky (AKSZ) construction encodes all the data of a topological sigma-model in the finite-dimensional symplectic $Q$-manifold. Relaxing the nondegeneracy condition i.e. considering a presymplectic form instead, extends the construction to non-topological models. The gauge-invariant action functional of (presymplectic) AKSZ sigma model is written in terms of space-time differential forms and can be seen as a covariant multidimensional analogue of the usual 1st order Hamiltonian action. In this work, we show that the AKSZ construction has a natural generalisation where the target space $Q$-manifold is equipped with a form of arbitrary degree $\Omega$ (possibly inhomogeneous) which is $(\mathrm{d}+L_Q)$-closed. This data defines a higher-derivative generalisation of the AKSZ action which is still invariant under the natural gauge transformations determined by $Q$ and which is efficiently formulated in terms of a version of Chern-Weil map introduced by Kotov and Strobl. It turns out that a variety of interesting gauge theories, including higher-dimensional Chern-Simons theory, MacDowell-Mansouri-Stelle-West action and self-dual gravity as well as its higher spin extension, can be concisely reformulated as such multisymplectic AKSZ models. We also present a version of the construction in the setup of PDE geometry and demonstrate that the counterpart of the multisymplectic AKSZ action is precisely the standard multisymplectic formulation, where the Chern-Weil map corresponds to the usual pullback map.

hep-th↗

arXiv2025

Higher-Spin Poisson Sigma Models and Holographic Duality for SYK Models

SYK models provide an interesting playground for exploring the $AdS_2/CFT_1$ correspondence. We focus on a class of SYK models that exhibit higher-spin symmetry, whose gravity sector is described by a BF theory generalizing Jackiw--Teitelboim gravity to higher spins. We further develop this framework by constructing consistent interactions between higher-spin gauge fields and scalar matter fields. Two concrete realizations are proposed: Model A, arising from a deformation of the universal enveloping algebra of $\mathfrak{sl}(2,\mathbb{R})$, and Model B, a perturbatively local Poisson sigma-model with an infinite-dimensional target space. While both capture higher-spin dynamics on $(A)dS_2$, they differ in their algebraic structures and locality properties, thus offering complementary perspectives on higher-spin holography.

hep-th↗

arXiv2025

Higher-spins on Taub-NUT and higher-spin Taub-NUT

We consider higher-spin extensions of self-dual Yang-Mills (HS-SDYM) and self-dual Gravity (HS-SDGR), which are also truncations of chiral higher-spin gravity. Higher-spin fields can consistently propagate on gravitational instantons and we construct solutions to the higher-spin equations on the Taub-NUT background. We show that these solutions remain exact solutions of HS-SDYM. For HS-SDGR the perturbation theory converges for any given spin to give a higher-spin generalization of Taub-NUT and we identify a commutative non-associative algebra that governs the structure of the perturbation theory.

hep-th↗

arXiv2025

Logica-TGD: Transforming Graph Databases Logically

Graph transformations are a powerful computational model for manipulating complex networks, but handling temporal aspects and scalability remain significant challenges. We present a novel approach to implementing these transformations using Logica, an open-source logic programming language and system that operates on parallel databases like DuckDB and BigQuery. Leveraging the parallelism of these engines, our method enhances performance and accessibility, while also offering a practical way to handle time-varying graphs. We illustrate Logica's graph querying and transformation capabilities with several examples, including the computation of the well-founded solution to the classic "Win-Move" game, a declarative program for pathfinding in a dynamic graph, and the application of Logica to the collection of all current facts of Wikidata for taxonomic relations analysis. We argue that clear declarative syntax, built-in visualization and powerful supported engines make Logica a convenient tool for graph transformations.

cs.DB↗

arXiv2024

Scalar Field on a higher-spin Background via Fedosov quantization

Conformal higher-spin gravity is the log-divergent part of the effective action of the scalar field coupled to background fields via higher-spin currents, as was defined by Segal and Tseytlin, which can be worked out over the flat space background. We revisit the problem of the scalar field in a higher-spin background and propose a manifestly covariant version thereof. The construction utilizes the Fedosov quantization of the cotangent bundle and the action is written with the help of the trace on a curved phase space that is provided by the Feigin--Felder--Shoikhet cocycle. The same construction allows one to formulate quantum mechanics on a curved space, the phase space being the cotangent bundle.

hep-th↗

arXiv2024

Electromagnetic Interactions of Massive Higher-Spin Fields in 3D via Chiral Theory

We address the issue of electromagnetic interaction for massive higher-spin fields in $3d$ Minkowski space. We show that consistent field equations can be obtained through the dimensional reduction of the higher-spin extension of self-dual Yang-Mills theory, which itself is a truncation of chiral higher-spin gravity in four dimensions. The resulting electromagnetic field satisfies the Bogomolny equation, and the interaction is non-minimal with the gyromagnetic ratio given by $g=1/s$, where $s$ is the spin. As a by-product, we obtain a new Lagrangian for free massive higher-spin fields in $3d$.

hep-th↗

arXiv2024

Matter-coupled higher spin gravities in 3d: no- and yes-go results

Massless higher-spin fields show no preference for any value of the cosmological constant in $3d$. All matter-free higher-spin gravities in 3d are equivalent to Chern-Simons theories with an appropriate choice of gauge algebra. For various reasons, including holography, it is important to enrich them with matter fields. In $(A)dS_3$, the coupling of matter fields to higher-spin fields is well-known to the leading order and is determined by the representation theory. We extend this result to flat space, where the relevant higher-spin algebra is the Poisson algebra, aka $w_{1+\infty}$. However, we show that both in flat and $(A)dS_3$ spaces there are no nontrivial higher order deformations/interactions. Nevertheless, by enlarging the field content with some auxiliary fields and taking advantage of the chiral higher-spin gravity's vertices, it is possible to construct an exotic matter-coupled theory on $(A)dS_3$. It also admits a flat limit. The equations of motion have the form of a Poisson sigma-model and a meaningful action has the form of a Courant sigma-model. We also explore the potential for embedding this theory into a holographic duality.

hep-th↗

arXiv2024

Massive spin three-half field in a constant electromagnetic background

Massive higher-spin fields are difficult to introduce consistent interactions, including electromagnetic and gravitational ones which are clearly exhibited by (non-elementary) higher-spin particles in nature. We construct an action that describes consistent interactions of massive spin three-half field with a constant electromagnetic background. We also work out the relation to the chiral approach.

hep-th↗

arXiv2024

Symmetric vs. chiral approaches to massive fields with spin

Massive higher spin fields are notoriously difficult to introduce interactions when they are described by symmetric (spin)-tensors. An alternative approach is to use chiral description that does not have unphysical longitudinal modes. For low spin fields we show that chiral and symmetric approaches can be related via a family of invertible change of variables (equivalent to parent actions), which should facilitate introduction of consistent interactions in the symmetric approach and help to control parity in the chiral one. We consider some examples of electromagnetic and gravitational interactions and their transmutations when going to the chiral formulation. An interesting feature of the relation is how second class constraints get eliminated while preserving Lorentz invariance.

hep-th↗

arXiv2024

Hidden sectors of Chern-Simons Matter theories and Exact Holography

Chiral higher-spin gravity is a higher-spin extension of both self-dual Yang-Mills and self-dual gravity and is a unique local higher-spin gravity in four dimensions. Its existence implies that there are two closed subsectors in Chern-Simons matter theories. We make first steps in identifying these (anti-)chiral subsectors directly on the CFT side, which should result in a holographically dual pair where both sides are nontrivial, complete, yet exactly soluble. We also discuss closely related theories: self-dual Yang-Mills (SDYM) and self-dual gravity (SDGR) in the holographic context.

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