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## Translation numbers define generators of F+k → Homeo+(S1)

Moscow Mathematical Journal. 2014. Vol. 14. No. 2. P. 291-308.

Volk D., Kleptsyn V., Gorodetski A., Golenishcheva-Kutuzova T.

We consider a minimal action of a finitely generated semigroup by homeomorphisms of the circle, and show that the collection of translation numbers of individual elements completely determines the set of generators (up to a common continuous change of coordinates). One of the main tools used in the proof is the synchronization properties of random dynamics of circle homeomorphisms: Antonov’s theorem and its corollaries.

Gusein-Zade S., Symmetry, Integrability and Geometry: Methods and Applications (SIGMA) 2020 Vol. 16 No. 051 P. 1-15

P. Berglund, T. Hübsch, and M. Henningson proposed a method to construct mirror symmetric Calabi–Yau manifolds. They considered a pair consisting of an invertible polynomial and of a finite (abelian) group
of its diagonal symmetries together with a dual pair. A. Takahashi suggested a method to generalize this construction to symmetry groups generated by some diagonal ...

Added: October 27, 2020

Blank M., Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2015 Т. 461 № 2 С. 1-5

We study the functional properties of the concept of interlacing introduced by I.M. Gelfand and show that in the context of collective random walks, this property leads to synchronization. ...

Added: March 20, 2015

On determinants of modified Bessel functions and entire solutions of double confluent Heun equations

Glutsyuk A., Buchstaber V., Nonlinearity 2016 Vol. 29 No. 12 P. 3857-3870

We investigate the question on existence of entire solutions of well-known linear differential
equations that are linearizations of nonlinear equations modeling the Josephson effect in superconductivity.
We consider the modified Bessel functions $I_j(x)$ of the first kind, which are Laurent series coefficients of the analytic
function family $e^{\frac x2(z+\frac 1z)}$. For every $l\geq1$ we study the family parametrized ...

Added: February 16, 2017

On determinants of modified Bessel functions and entire solutions of double confluent Heun equations

Buchstaber V.M., Glutsyuk A. A., Nonlinearity 2016 Vol. 29 No. 12 P. 3857-3870

We investigate the question on existence of entire solutions of well-known linear differential equations that are linearizations of nonlinear equations modeling the Josephson effect in superconductivity. We consider the modified Bessel functions Ij(x) of the first kind, which are Laurent series coefficients of the analytic function family . For every we study the family parametrized by , , of -matrix functions formed ...

Added: June 17, 2021

Alvarez S., Filimonov D., Kleptsyn V. et al., Journal of Topology 2019 Vol. 12 No. 4 P. 1315-1367

This article is inspired by two milestones in the study of non-minimal group actions on the circle: Duminy's theorem about the number of ends of semi-exceptional leaves, and Ghys' freeness result in real-analytic regularity. Our first result concerns groups of real-analytic diffeomorphisms with infinitely many ends: if the action is non expanding, then the group ...

Added: July 13, 2019

Klimenko A. V., Bufetov A. I., Труды Математического института им. В.А. Стеклова РАН 2012 Т. 277 С. 33-48

Устанавливается сходимость почти всюду средних по Чезаро сферических средних произвольной функции из класса L^p, p>1, для действий марковских полугрупп, и в частности конечно порожденных гиперболических групп. ...

Added: February 13, 2013

V. L. Popov, Izvestiya: Mathematics, England 2019 Vol. 83 No. 4 P. 830-859

The first group of results of this paper concerns the compressibility of finite subgroups of the Cremona groups. The second concerns the embeddability of other groups in the Cremona groups and, conversely, the Cremona groups in
other groups. The third concerns the connectedness of the Cremona groups. ...

Added: September 29, 2019

Manita A., Lobachevskii Journal of Mathematics 2017 Vol. 38 No. 5 P. 948-953

We introduce a class of stochastic networks in which synchronization between nodes is modelled by a message passing mechanism with heterogeneous Markovian routing. We present a series of results about probability distribution related to steady states of such models. ...

Added: June 20, 2017

Glutsyuk A., Bibilo Y., On families of constrictions in model of overdamped Josephson junction and Painlevé 3 equation / Cornell University. Series arXiv "math". 2021. No. 2011.07839.

We study family of dynamical systems on 2-torus modeling over-damped Josephson junction in superconductivity. It depends on three parameters (B,A;ω): B (abscissa), A(ordinate), ω (a fixed frequency).We study the rotation numberρ(B,A;ω) as a function of (B,A) withfixedω. Aphase-lock areais the level set Lr:={ρ=r}, if it has an on-empty interior. This holds for r∈Z (a result ...

Added: November 26, 2020

Kleptsyn V., Alvarez S., Malicet D. et al., Groups with infinitely many ends acting analytically on the circle / Cornell University. Series math "arxiv.org". 2015.

Added: June 22, 2016

Glutsyuk A., Rybnikov L. G., Nonlinearity 2017 Vol. 30 No. 1 P. 61-72

We consider two-parametric families of non-autonomous ordinary differential equations on the two-torus with coordinates (x, t) of the type x'=v(x)+A+Bf(t). We study its rotation number as a function of the parameters (A, B). The phase-lock areas are those level sets of the rotation number function that have non-empty interiors. Buchstaber, Karpov and Tertychnyi studied the ...

Added: February 15, 2017

Ilya Schurov, Nikita Solodovnikov, Duck factory on the two-torus: multiple canard cycles without geometric constraints / Cornell University. Series math "arxiv.org". 2014. No. 1405.3251.

Slow-fast systems on the two-torus are studied. As it was shown before, canard cycles are generic in such systems, which is in drastic contrast with the planar case. It is known that if the rotation number of the Poincare map is integer and the slow curve is connected, the number of canard limit cycles is ...

Added: May 14, 2014

Dmitrichev A., Zakharov D., Nekorkin V., Radiophysics and Quantum Electronics 2017 Vol. 60 No. 6 P. 506-512

We study stability of a synchronous regime in hub clusters of the power networks, which are simulated by ensembles of phase oscillators. An approach allowing one to estimate the regions in the parameter space, which correspond to the global asymptotic stability of this regime, is presented. The method is illustrated by an example of a ...

Added: October 4, 2018

Gusein-Zade S., Mathematische Nachrichten 2018 Vol. 291 No. 17-18 P. 2543-2556

Let a finite abelian group G act (linearly) on the space R^n and thus on its complexification C^n. Let W be the real part of the quotient C^n/G (in general W \neq R^n/G). We give an algebraic formula for the radial index of a 1-form \omega on the real quotient W. It is shown that ...

Added: October 27, 2020

Buff X., Goncharuk Nataliya, Journal of Modern Dynamics 2015 Vol. 9 P. 169-190

We investigate the notion of complex rotation number which was introduced by V.I.Arnold in 1978. Let f: R/Z -> R/Z be a (real) analytic orientation preserving circle diffeomorphism and let omega in C/Z be a parameter with positive imaginary part. Construct a complex torus by glueing the two boundary components of the annulus { z ...

Added: October 10, 2013

Filimonov D., Клепцын В. А., Nonlinearity 2014 Vol. 27 No. 6 P. 1205-1223

We study possible one-end finitely presented subgroups of <img />, acting without finite orbits. Our main result, theorem 1, establishes that any such action possesses the so-called property (<img />), that allows one to make distortion-controlled expansion and is thus sufficient to conclude that the action is Lebesgue-ergodic. We also propose a path towards full ...

Added: October 23, 2014

Gusein-Zade S., Математические заметки 2020 Т. 107 № 6 С. 855-864

V.I.Arnold has classified simple (i.e., having no moduli for the classification) singularities (function germs), and also simple boundary singularities: function germs invariant with respect to the action σ (x1; y1, …, yn) = (−x1; y1, …, yn) of the group ℤ2. In particular, it was shown that a function germ (a boundary singularity germ) is ...

Added: October 27, 2020

Gusein-Zade S., Раух А. Я., Функциональный анализ и его приложения 2021 Т. 55 № 1 С. 56-64

V.I.Arnold classified simple (i.e. having no moduli for the classification) singularities (function germs) and also simple boundary singularities: function germs invariant with respect to the action
σ(x1;y1,…,yn)=(−x1;y1,…,yn) of the group Z2. In particular, it was shown that a function germ (a germ of a boundary singularity) is simple if and only if the intersection form (respectively, ...

Added: February 3, 2021

Ebeling W., Gusein-Zade S., International Mathematics Research Notices 2021 Vol. 2021 No. 16 P. 12305-12329

A.Takahashi suggested a conjectural method to find mirror symmetric pairs consisting of invertible polynomials and symmetry groups generated by some diagonal symmetries and some permutations of variables. Here we generalize the Saito duality between Burnside rings to a case of non-abelian groups and prove a "non-abelian" generalization of the statement about the equivariant Saito duality ...

Added: August 26, 2021

Gusein-Zade S., Функциональный анализ и его приложения 2018 Т. 52 № 2 С. 78-81

Let G be a finite Abelian group acting (linearly) on space ℝn and, therefore, on its complexification ℂn, and let W be the real part of the quotient ℂn/G (in the general case, W ≠ ℝn/G). The index of an analytic 1-form on the space W is expressed in terms of the signature of the ...

Added: October 27, 2020

Glutsyuk A., Journal of Dynamical and Control Systems 2019 Vol. 25 No. 3 P. 323-349

In 1973, B. Josephson received a Nobel Prize for discovering a new fundamentaleffect concerning a Josephson junction,—a system of two superconductors separated by a very narrow dielectric: there could exist a supercurrent tunneling through this junction. We will discuss the model of the overdamped Josephson junction, which is given by a family of first-order nonlinear ...

Added: August 20, 2018

Попов В. Л., Известия РАН. Серия математическая 2019 Т. 84 № 4 С. 194-225

The rst group of results of this paper concerns the compressibility of finite subgroups of the Cremona groups. The second concerns the embeddability of other groups in the Cremona groups and, conversely, the Cremona groups in
other groups. The third concerns the connectedness of the Cremona groups. ...

Added: July 31, 2019

Schurov I., Клепцын В. А., Romaskevich O. L., Наноструктуры. Математическая физика и моделирование 2013 Т. 8 № 1 С. 31-46

In order to model the processes taking place in systems with Josephson contacts, a differential equation on a torus with three parameters is used. One of the parameters of the system can be considered small and the methods of the fast-slow systems theory can be applied. The properties of the phase-lock areas – the subsets ...

Added: December 17, 2014

A. Klimenko, O. Romaskevich, Moscow Mathematical Journal 2014 Vol. 14 No. 2 P. 367-384

A three-parametrical family of ODEs on a torus arises from a model of Josephson effect in a resistive case when a Josephson junction is biased by a sinusoidal microwave current. We study asymptotics of Arnold tongues of this family on the parametric plane (the third parameter is fixed) and prove that the boundaries of the ...

Added: September 5, 2014