{"title":"Sonya Kowalewski’s Legacy to Mechanics and Complex Lie Algebras","authors":"Velimir Jurdjevic","doi":"10.1134/S1560354725050028","DOIUrl":"10.1134/S1560354725050028","url":null,"abstract":"<div><p>This paper provides an original rendition of the heavy top that unravels the mysteries behind S. Kowalewski’s seminal work on the motions of a rigid body around a fixed point under the influence of gravity.\u0000The point of departure for understanding Kowalewski’s work\u0000begins with Kirchhoff’s model for the equilibrium configurations of an elastic rod in <span>({mathbb{R}}^{3})</span> subject to fixed bending and twisting moments at its ends [17]. This initial orientation to the elastic problem shows, first, that the Kowalewski type integrals discovered by I. V. Komarov and V. B. Kuznetsov [24, 25] appear naturally on the Lie algebras associated with the orthonormal frame bundles of the sphere <span>(S^{3})</span> and the hyperboloid <span>(H^{3})</span> [17] and, secondly, it shows\u0000that these integrals of motion can be naturally extracted from a canonical Poisson system on the dual of <span>(so(4,mathbb{C}))</span> generated by\u0000an affine quadratic Hamiltonian <span>(H)</span> (Kirchhoff – Kowalewski type).</p><p>The paper shows that the passage to complex variables\u0000is synonymous with the representation of <span>(so(4,mathbb{C}))</span> as <span>(sl(2,mathbb{C})times sl(2,mathbb{C}))</span> and the embedding of <span>(H)</span> into <span>(sp(4,mathbb{C}))</span>, an important intermediate step towards uncovering the origins of Kowalewski’s integral. There is a quintessential Kowalewski type integral of motion on <span>(sp(4,mathbb{C}))</span> that appears as a spectral invariant for the Poisson system associated with a Hamiltonian <span>(mathcal{H})</span> (a natural extension of <span>(H)</span>) that satisfies Kowalewski’s conditions.</p><p>The text then demonstrates the relevance of this integral of motion for other studies in the existing literature [7, 35]. The text also includes a self-contained treatment of the integration of the Kowalewski type equations based on Kowalewski’s ingenuous separation of variables, the hyperelliptic curve and the solutions on its Jacobian variety.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"767 - 798"},"PeriodicalIF":0.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256372","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":"Painlevé Test, First Integrals and Exact Solutions of Nonlinear Dissipative Differential Equations","authors":"Nikolay A. Kudryashov","doi":"10.1134/S1560354725050041","DOIUrl":"10.1134/S1560354725050041","url":null,"abstract":"<div><p>The Korteweg – de Vries – Burgers equation, the modified Korteweg – de Vries – Burgers equation, the dissipative Gardner equation and the nonlinear differential equation for description surface waves in a convecting fluid are considered. The Cauchy problems for all these partial differential equations are not solved by the\u0000inverse scattering transform. Reductions of these equations to nonlinear ordinary differential\u0000equations do not pass the Painlevé test. However, there are local expansions of the general\u0000solutions in the Laurent series near movable singular points.\u0000We demonstrate that the obtained information from the Painlevé test for reductions of\u0000nonlinear evolution dissipative differential equations can be used to construct the\u0000nonautonomous first integrals of nonlinear ordinary differential equations. Taking into\u0000account the found first integrals, we also obtain analytical solutions of nonlinear evolution\u0000dissipative differential equations. Our approach is illustrated to obtain the\u0000nonautonomous first integrals for reduction of the Korteweg – de Vries – Burgers equation,\u0000the modified Korteweg – de Vries – Burgers equation, the dissipative Gardner equation and\u0000the nonlinear differential equation for description surface waves in a convecting fluid.\u0000The obtained first integrals are used to construct exact solutions of the above-mentioned\u0000nonlinear evolution equations with as many arbitrary constants as possible. It is shown that\u0000some exact solutions of the equation for description of nonlinear waves in a convecting\u0000liquid are expressed via the Painlevé transcendents.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"819 - 836"},"PeriodicalIF":0.8,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145256268","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":"Periodic Response Solutions to Multidimensional Nonlinear Schrödinger Equations with Unbounded Perturbation","authors":"Zuhong You, Xiaoping Yuan","doi":"10.1134/S1560354725530048","DOIUrl":"10.1134/S1560354725530048","url":null,"abstract":"<div><p>This paper establishes the existence of periodic response solutions for multi-dimensional nonlinear Schrödinger equations (NLS) with unbounded perturbations. We adapt the Craig – Wayne – Bourgain (CWB) method to this context. The central point is that the core separation lemma remains valid for sufficiently weak unbounded perturbations, which allows the CWB method to be successfully applied. This work extends the applicability of the CWB method to problems with unbounded perturbations.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"31 3","pages":"438 - 452"},"PeriodicalIF":0.8,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148060748","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":"Computation of Periodic Libration Point Orbits in the Circular Restricted Three-Body Problem","authors":"Daniella Gafurova, Sergey Aksenov","doi":"10.1134/S1560354725530024","DOIUrl":"10.1134/S1560354725530024","url":null,"abstract":"<div><p>The circular restricted three-body problem is used as an approximate model in space mission planning. Its periodic solutions around equilibrium points, which are referred to as the libration points, are utilized for exploration of possible spacecraft trajectories in the preliminary stages of mission design. In this paper, a numerical methodology for periodic libration point orbits (LPOs) computation is introduced and applied to the construction and study of <i>N</i>-periodic (up to <span>(N=6)</span>) quasi-planar orbit families in the Earth-Moon system. The stability and the bifurcation points of these families are determined. The proposed method is based on an iterative algorithm searching for the initial state vector of periodic LPOs, which allows computing unstable long-periodic and large-amplitude orbits. The method is suited to perform a straightforward switch to bifurcating branches of periodic orbits.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"30 Editors:","pages":"969 - 991"},"PeriodicalIF":0.8,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646213","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}
Gerson C. Araujo, Keity Murielly J. de Andrade, José Laudelino de Menezes Neto
{"title":"Parametric Stability of a Charged Pendulum with an Oscillating Suspension Point Located above Two Electric Charges of the Same Intensity and Sign,\u0000Equally Distant from the Suspension Point","authors":"Gerson C. Araujo, Keity Murielly J. de Andrade, José Laudelino de Menezes Neto","doi":"10.1134/S1560354725530012","DOIUrl":"10.1134/S1560354725530012","url":null,"abstract":"<div><p>In this study, we analyze a planar mathematical pendulum whose suspension point oscillates vertically according to a harmonic law. The pendulum bob is electrically charged and positioned slightly above two electric charges of equal sign and intensity, which are equidistant from the suspension point and separated by a distance of <span>(2d.)</span> Here, <span>(d)</span> denotes the distance from each charge to the orthogonal projection of the suspension point onto the horizontal line where the charges lie. We formulate the Hamiltonian structure of this mechanical system, identify two equilibrium points, and examine the system’s linear stability. The dynamics are governed by three dimensionless\u0000parameters: <span>(mu)</span> which relates to the electric charges; <span>(varepsilon,)</span> associated with the amplitude of oscillation of the suspension point; and <span>(alpha,)</span> determined by the frequency of the system. We then investigate the parametric stability of the equilibrium points. Finally, we present the boundary surfaces that separate regions of stability and instability in the parameter space. For specific values of <span>(mu,)</span> we derive cross-sectional curves that delineate these regions, using results from the Krein – Gelfand – Lidskii theorem and the Deprit – Hori\u0000method.</p></div>","PeriodicalId":752,"journal":{"name":"Regular and Chaotic Dynamics","volume":"31 3","pages":"484 - 501"},"PeriodicalIF":0.8,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148060750","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}