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Kirill Gubarev

Publications and source records attributed to Kirill Gubarev.

16 recordsLinked to original sources
arXiv2026

Non-abelian uni-vector deformations in gauged supergravities and non-abelian Einstein-Maxwell theories

We construct non-abelian uni-vector deformations of solutions in non-abelian Einstein\--Maxwell theories and gauged supergravities, obtained as Scherk--Schwarz reductions of general relativity and double field theory, respectively. We provide examples of deformed backgrounds for both cases. We show that non-abelian deformations in Einstein--Maxwell theories can be presented as coordinate transformations in the parent theory, general relativity, extending the result of arXiv:2508.09637 for abelian uni-vector deformations.

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arXiv2026

Limits of the inverse scattering problem

The main goal of tomography is the reconstruction of density function out of its line integrals (integral measurements of this density along x-ray lines). Such construction is possible and known as inverse x-ray/Radon transformations. We are interested in generalization of this problem to the case of particles. For this we need to limit the speed of these particles, otherwise the problem is reduced to the previous one. The question we discuss in this paper is how low can this speed be depending on the parameters of the studied potential. We study this problem using simple theoretical examples and Machine Learning pipeline to restore the potential.

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arXiv2026

Uni-vector deformations, D0-bound states and DLCQ

We investigate uni-vector deformation in the Type IIA setup and show that the D0-brane background is mapped into itself (sedimentation), and other extremal backgrounds get bound with a dissolved D0-brane charge. Explicitly we generate F1-D0 and D2-D0 bound states background from uni-vector deformations. For the former we show that deformation of the non-extremal string gives the correct thermal F1-D0 bound state. We discuss relations between critical uni-vector deformations and DLCQ of M-theory.

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arXiv2026

Poly-vector deformations of heterotic supergravity solutions

We construct bi- and uni-vector deformations of 10d heterotic supergravity solutions with the gauged double field theory approach. We construct a generalization of the "open/closed" map for this case and consider some examples of the deformed solutions, particularly for the F1 string solution.

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arXiv2025

Brane bound states, deformations and OM

We investigate behavior of brane backgrounds under poly-vector deformations in Type IIB and D=11 supergravities. We find that the standard bi-vector deformations add dissolved F1 string charge to a Dp-brane background, quadri-vector deformations add D3-brane charge, tri- and six-vector deformations in D=11 add M2- and M5-brane charges respectively. We discuss these results in the context of NRCS and OM theories.

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arXiv2025

Yang-Baxter structure of the extended space

We construct an analogue of Yang--Baxter deformations defined by a single Killing vector, that is a solution generating transformation in Einstein--Maxwell dilaton theory. We show that these are nothing but a coordinate transformation in a parent theory related to EMd theory by KK reduction. Similarly (almost-abelian) bi-vector Yang--Baxter deformations are coordinate transformations in the doubled space.

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arXiv2024

Tri-vector deformations with external fluxes

We extend the formalism of tri-vector deformations to the full SL(5) exceptional field theory with no truncation assumed thus covering 11D backgrounds of any form. We derive explicit transformation rules for 11D supergravity component fields and prove that these generate solutions given the same algebraic conditions hold: generalized Yang-Baxter equation and the unimodularity condition.

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arXiv2024

Polyvector deformations of Type IIB backgrounds

We develop a formalism of poly-vector deformations for Type IIB backgrounds with a block diagonal metric and non-vanishing self-dual 5-form RR field strength. Making use of the embedding of the Type IIB theory into the $\mathrm{E}_{6(6)}$ exceptional field theory we derive explicit transformation rules for four-vector deformations. We prove that the algebraic condition following from the Type IIB realization of exceptional Drinfeld algebras is sufficient for the transformation to generate a solution.

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arXiv2024

Holographic RG flows and boundary conditions in a 3D gauged supergravity

In this work we focus on the study of RG flows of conformal field theories that are holographically dual to Poincaré domain wall solutions in $D=3$, $\mathcal{N}=(2,0)$ gauged supergravity coupled to a sigma model with target space $SU(1, 1)/U(1) = H^2$. This theory is truncated to a subsector where the vector field and phase of the scalar field vanish and we consider different boundary conditions for the remaining real scalar field. The RG flows, which are mostly non-superysymmetric, are analyzed by treating the supergravity field equations as a dynamical system for the scalar field and its derivative with respect to the scale factor. Phase diagrams are constructed for different values of the parameter $a^2$, which is related to the curvature of the scalar manifold. The behavior of solutions near the boundary is used to determine their type based on the expansion of the corresponding fake superpotential. By incorporating information on the boundary conditions, the obtained RG flows are interpreted using the holographic dictionary. Numerical solutions and plots of the fake superpotential are also provided.

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arXiv2023

Exotic potentials and Bianchi identities in SL(5) exceptional field theory

Tensor hierarchy of Exceptional Field Theories contains gauge fields satisfying certain Bianchi identities. We define the full set of fluxes of the SL(5) exceptional field theory containing known gauge field strengths, generalized anholonomy coefficients and two new fluxes. It is shown that the full SL(5) ExFT Lagrangian can be written in terms of the listed fluxes. We derive the complete set of Bianchi identities and identify magnetic potentials of the theory and the corresponding (wrapped) membranes of M-theory.

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arXiv2023

Integrability structures in string theory

This review is a collection of various methods and observations relevant to structures in three-dimensional systems similar to those responsible for integrability of two-dimensional systems. Particular focus is given to Nambu structures and loop variables naturally appearing in membrane dynamics. While reviewing each topic in more details we emphasize connections between them and speculate on possible relations to membrane integrability.

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arXiv2022

Generalized 11D supergravity equations from tri-vector deformations

In arXiv:2203.03372 we presented a modification of 11-dimensional supergravity field equations which upon dimensional reduction yields generalized supergravity equations in 10-dimensions. In this paper we provide full technical details of that result which is based on SL(5) exceptional field theory. The equations are obtained by making a non-unimodular tri-vector Yang-Baxter deformation which breaks the initial GL(11) symmetry down to GL(7)xGL(4). We also give some non-trivial solutions to these equations.

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arXiv2022

Generalizing eleven-dimensional supergravity

We develop a procedure to reproduce the ten-dimensional generalized supergravity equations from T-duality covariant equations, that facilitates generalization to U-duality covariant formulations of eleven-dimensional supergravity. The latter leads to a modification of the eleven-dimensional supergravity equations with terms that contain a rank-2 tensor field $J^{mn}$ which is the eleven-dimensional analog of the non-unimodularity Killing vector $I^m$ in ten dimensions.

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arXiv2020

Polyvector deformations in eleven-dimensional supergravity

We consider 3- and 6-vector deformations of 11-dimensional supergravity backgrounds of the form $M_5\times M_6$ admitting at least 3 Killing vectors. Using flux formulation of the E${}_{6(6)}$ exceptional field theory we derive (sufficient) conditions for the deformations to generate a solution. In the group manifold case these generalisations of the classical Yang-Baxter equation for the case of r-matrices with 3 and 6 indices are shown to reproduce those obtained from exceptional Drinfeld algebra for E${}_{6(6)}$. In general we see an additional constraint, which might be related to higher exceptional Drinfeld algebras.

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arXiv2020

Non-abelian tri-vector deformations in d=11 supergravity

A truncation of the SL(5) Exceptional Field Theory that allows to describe spacetimes of the form $M_4 \times M_7$ with the 4-form flux on $M_4$ is constructed. The resulting theory is used to test the recently proposed tri-vector generalisation of Yang-Baxter deformations applied to the AdS${}_4 \times \mathbb{S}^7$ solution in $d=11$ supergravity. We present two new supergravity solutions corresponding to non-abelian non-unimodular tri-vector deformations of AdS${}_4 \times \mathbb{S}^7$.

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