{"title":"Lyapunov Exponents of Linear Switched Systems","authors":"Andrei A. Agrachev, Michele Motta","doi":"10.1134/S1560354725040033","DOIUrl":"10.1134/S1560354725040033","url":null,"abstract":"<div><p>We explicitly compute the maximal Lyapunov exponent for a switched system on <span>(mathrm{SL}_{2}(mathbb{R}))</span> and the corresponding switching function which realizes the maximal exponent. This computation is reduced to the characterization of optimal trajectories for an optimal control problem on the Lie group.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"481 - 503"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the Picard – Lindelöf Argument and the Banach – Caccioppoli Contraction Mapping Principle","authors":"Alexander I. Bufetov, Ilya I. Zavolokin","doi":"10.1134/S1560354725040070","DOIUrl":"10.1134/S1560354725040070","url":null,"abstract":"<div><p>The aim of this note is to present a simple observation that a slight refinement of the\u0000contraction mapping principle allows one to recover the precise convergence rate in the\u0000Picard – Lindelöf theorem.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"566 - 581"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metric Geometry and Forced Oscillations in Mechanical Systems","authors":"Ivan Yu. Polekhin","doi":"10.1134/S1560354725040173","DOIUrl":"10.1134/S1560354725040173","url":null,"abstract":"<div><p>We consider the problem of existence of forced oscillations on a Riemannian manifold, the metric on which is defined by the kinetic energy of a mechanical system. Under the assumption that the generalized forces are periodic functions of time, we find periodic solutions of the same period. We present sufficient conditions for the existence of such solutions, which essentially depend on the behavior of geodesics on the corresponding Riemannian manifold.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"732 - 741"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Poncelet Porism in Singular Cases","authors":"Vladimir Dragović, Milena Radnović","doi":"10.1134/S1560354725040094","DOIUrl":"10.1134/S1560354725040094","url":null,"abstract":"<div><p>The celebrated Poncelet porism is usually studied for a pair of smooth conics that are in a general position. Here we discuss Poncelet porism in the real plane — affine or projective, when that is not the case, i. e., the conics have at least one point of tangency or at least one of the conics is not smooth.\u0000In all such cases, we find necessary and sufficient conditions for the existence of an <span>(n)</span>-gon inscribed in one of the conics and circumscribed about the other.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"598 - 611"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Infinite-Dimensional and Field-Theoretic Nonholonomic Mechanics","authors":"Anthony M. Bloch, Dmitry V. Zenkov","doi":"10.1134/S1560354725040069","DOIUrl":"10.1134/S1560354725040069","url":null,"abstract":"<div><p>Nonholonomic systems are mechanical systems with ideal velocity constraints that are not derivable from position constraints and with dynamics identified by the Lagrange – d’Alembert principle.\u0000This paper reviews infinite-dimensional and field-theoretic nonholonomic systems as well as Hamel’s formalism for these settings.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"550 - 565"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Billiard Trajectories inside Cones","authors":"Andrey E. Mironov, Siyao Yin","doi":"10.1134/S156035472504015X","DOIUrl":"10.1134/S156035472504015X","url":null,"abstract":"<div><p>Recently it was proved that every billiard trajectory inside a <span>(C^{3})</span> convex cone has a finite number of reflections. Here, by a <span>(C^{3})</span> convex cone, we mean a cone whose section with some hyperplane is a strictly convex, closed <span>(C^{3})</span> hypersurface of that hyperplane, with an everywhere nondegenerate second fundamental form. In this paper, we prove that there exist <span>(C^{2})</span> convex cones with billiard trajectories that undergo infinitely many reflections in finite time. We also provide an estimation of the number of reflections for billiard trajectories inside elliptic cones in <span>(mathbb{R}^{3})</span> using two first integrals.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"688 - 710"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Real Analyticity of 2-Dimensional Superintegrable Metrics and Solution of Two Bolsinov – Kozlov – Fomenko Conjectures","authors":"Vladimir S. Matveev","doi":"10.1134/S1560354725040148","DOIUrl":"10.1134/S1560354725040148","url":null,"abstract":"<div><p>We study two-dimensional Riemannian metrics which are superintegrable in the class of\u0000integrals polynomial in momenta.\u0000The study is based on our main technical result, Theorem 2, which states that the\u0000Poisson bracket of two integrals polynomial in momenta is an algebraic function of\u0000the integrals and of the Hamiltonian. We conjecture that two-dimensional superintegrable Riemannian metrics are necessarily real-analytic in isothermal coordinate systems, and give arguments supporting this conjecture. A small modification of the arguments, discussed in the paper, provides a method to construct new superintegrable systems. We prove a special case of the above conjecture which is sufficient to show that\u0000the metrics constructed by K. Kiyohara [9], which admit irreducible\u0000integrals polynomial in momenta, of arbitrary high degree <span>(k)</span>, are not superintegrable and\u0000in particular do not admit nontrivial integrals polynomial in momenta, of degree less\u0000than <span>(k)</span>. This result solves Conjectures (b) and (c) explicitly formulated in [4].</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"677 - 687"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Santiago Barbieri, Luca Biasco, Luigi Chierchia, Davide Zaccaria
{"title":"Singular KAM Theory for Convex Hamiltonian Systems","authors":"Santiago Barbieri, Luca Biasco, Luigi Chierchia, Davide Zaccaria","doi":"10.1134/S1560354725040057","DOIUrl":"10.1134/S1560354725040057","url":null,"abstract":"<div><p>In this note, we briefly discuss how the singular KAM theory of [7] — which was worked out for the mechanical case <span>(frac{1}{2}|y|^{2}+varepsilon f(x))</span> — can be extended to <i>convex</i> real-analytic\u0000nearly integrable Hamiltonian systems\u0000with Hamiltonian in action-angle variables given by <span>(h(y)+varepsilon f(x))</span> with <span>(h)</span> convex and\u0000<span>(f)</span> generic.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"538 - 549"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Lorentzian Anti-de Sitter Plane","authors":"Anton Z. Ali, Yuri L. Sachkov","doi":"10.1134/S1560354725040045","DOIUrl":"10.1134/S1560354725040045","url":null,"abstract":"<div><p>In this paper the two-dimensional Lorentzian problem on the anti-de Sitter plane is studied. Using methods of geometric control theory and differential geometry, we describe the reachable set, investigate the existence of Lorentzian length maximizers, compute extremal trajectories, construct an optimal synthesis, characterize Lorentzian distance and spheres, and describe the Lie algebra of Killing vector fields.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"504 - 537"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On Tensor Invariants of the Clebsch System","authors":"Andrey V. Tsiganov","doi":"10.1134/S1560354725040185","DOIUrl":"10.1134/S1560354725040185","url":null,"abstract":"<div><p>We present some new Poisson bivectors that are invariants by the Clebsch system flow. Symplectic integrators on their symplectic leaves exactly preserve the corresponding Casimir functions, which have different physical meanings. The Kahan discretization of the Clebsch system is discussed briefly.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"742 - 764"},"PeriodicalIF":0.8,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145121791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}