{"title":"Relative periodic solutions of the begin{document}$ n $end{document}-vortex problem on the sphere","authors":"C. García-Azpeitia","doi":"10.3934/JGM.2019021","DOIUrl":"https://doi.org/10.3934/JGM.2019021","url":null,"abstract":"This paper gives an analysis of the movement of begin{document}$ n $end{document} vortices on the sphere. When the vortices have equal circulation, there is a polygonal solution that rotates uniformly around its center. The main result concerns the global existence of relative periodic solutions that emerge from this polygonal relative equilibrium. In addition, it is proved that the families of relative periodic solutions contain dense sets of choreographies.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"29 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89539586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Generalized point vortex dynamics on begin{document}$ mathbb{CP} ^2 $end{document}","authors":"J. Montaldi, Amna Shaddad","doi":"10.3934/jgm.2019030","DOIUrl":"https://doi.org/10.3934/jgm.2019030","url":null,"abstract":"This is the second of two companion papers. We describe a generalization of the point vortex system on surfaces to a Hamiltonian dynamical system consisting of two or three points on complex projective space begin{document}$ mathbb{CP} ^2 $end{document} interacting via a Hamiltonian function depending only on the distance between the points. The system has symmetry group SU(3). The first paper describes all possible momentum values for such systems, and here we apply methods of symplectic reduction and geometric mechanics to analyze the possible relative equilibria of such interacting generalized vortices. The different types of polytope depend on the values of the 'vortex strengths', which are manifested as coefficients of the symplectic forms on the copies of begin{document}$ mathbb{CP} ^2 $end{document} . We show that the reduced space for this Hamiltonian action for 3 vortices is generically a 2-sphere, and proceed to describe the reduced dynamics under simple hypotheses on the type of Hamiltonian interaction. The other non-trivial reduced spaces are topological spheres with isolated singular points. For 2 generalized vortices, the reduced spaces are just points, and the motion is governed by a collective Hamiltonian, whereas for 3 the reduced spaces are of dimension at most 2. In both cases the system will be completely integrable in the non-abelian sense.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"19 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73263679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Non-Abelian momentum polytopes for products of begin{document}$ mathbb{CP}^2 $end{document}","authors":"J. Montaldi, Amna Shaddad","doi":"10.3934/jgm.2019029","DOIUrl":"https://doi.org/10.3934/jgm.2019029","url":null,"abstract":"This is the first of two companion papers. The joint aim is to study a generalization to higher dimension of the familiar point vortex systems in 2 dimensions. In this paper we classify the momentum polytopes for the action of the Lie group SU(3) on products of copies of complex projective 2-space (a real 4-dimensional manifold). For 2 copies, the momentum polytope is simply a line segment, which can sit in the positive Weyl chamber in a small number of ways. For a product of 3 copies there are 8 different types of generic momentum polytope, and numerous transition polytopes, all of which are classified here. The type of polytope depends on the weights of the symplectic form on each copy of projective space. In the second paper we use techniques of symplectic reduction to study the possible dynamics of interacting generalized point vortices. The results of this paper can be applied to determine the inequalities satisfied by the eigenvalues of the sum of up to three 3x3 Hermitian matrices where each has a double eigenvalue.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"43 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81066046","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":"Dual pairs for matrix groups","authors":"Paul Skerritt, Cornelia Vizman","doi":"10.3934/JGM.2019014","DOIUrl":"https://doi.org/10.3934/JGM.2019014","url":null,"abstract":"In this paper we present two dual pairs that can be seen as the linear analogues of the following two dual pairs related to fluids: the EPDiff dual pair due to Holm and Marsden, and the ideal fluid dual pair due to Marsden and Weinstein.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76776073","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":"Riemannian cubics and elastica in the manifold begin{document}$ operatorname{SPD}(n) $end{document} of all begin{document}$ ntimes n $end{document} symmetric positive-definite matrices","authors":"Erchuan Zhang, L. Noakes","doi":"10.3934/JGM.2019015","DOIUrl":"https://doi.org/10.3934/JGM.2019015","url":null,"abstract":"Left Lie reduction is a technique used in the study of curves in bi-invariant Lie groups [ 32 , 33 , 40 ]. Although the manifold begin{document}$ operatorname{SPD}(n) $end{document} of all begin{document}$ ntimes n $end{document} symmetric positive-definite matrices is not a Lie group with respect to the standard matrix multiplication, it is a symmetric space with a left action of begin{document}$ GL(n) $end{document} and an isotropy group begin{document}$ SO(n) $end{document} leaving the identity matrix fixed. The main purpose of this paper is to extend the method of left Lie reduction to begin{document}$ operatorname{SPD}(n) $end{document} and use it to study two second order variational curves: Riemannian cubics and elastica. Riemannian cubics in begin{document}$ operatorname{SPD}(n) $end{document} are reduced to so-called Lie quadratics in the Lie algebra begin{document}$ mathfrak{gl}(n) $end{document} and geometric analyses are presented. Besides, by using the Frenet-Serret frames and the extended left Lie reduction separately, we investigate elastica in the manifold begin{document}$ operatorname{SPD}(n) $end{document} . The latter presents a comparatively simple form of the equations for elastica in begin{document}$ operatorname{SPD}(n) $end{document} .","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"83 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91393647","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 integrals and partial differential equations for stochastic and quantum phenomena","authors":"S. Albeverio, S. Mazzucchi","doi":"10.3934/JGM.2019006","DOIUrl":"https://doi.org/10.3934/JGM.2019006","url":null,"abstract":"We present a survey of the relations between infinite dimensional integrals, both of the probabilistic type (e.g. Wiener path integrals) and of oscillatory type (e.g. Feynman path integrals). Besides their mutual relations (analogies and differences) we also discuss their relations with certain types of partial differential equations (parabolic resp. hyperbolic), describing time evolution with or without stochastic terms. The connection of these worlds of deterministic and stochastic evolutions with the world of quantum phenomena is also briefly illustrated. The survey spans a bridge from basic concepts and methods in these areas to recent developments concerning their relations.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83202764","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":"Riemann-Hilbert problem, integrability and reductions","authors":"V. Gerdjikov, R. Ivanov, A. Stefanov","doi":"10.3934/jgm.2019009","DOIUrl":"https://doi.org/10.3934/jgm.2019009","url":null,"abstract":"The present paper is dedicated to integrable models with Mikhailov reduction groups begin{document}$G_R simeq mathbb{D}_h.$end{document} Their Lax representation allows us to prove, that their solution is equivalent to solving Riemann-Hilbert problems, whose contours depend on the realization of the begin{document}$G_R$end{document} -action on the spectral parameter. Two new examples of Nonlinear Evolution Equations (NLEE) with begin{document}$mathbb{D}_h$end{document} symmetries are presented.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"47 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79226852","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":"De Donder form for second order gravity","authors":"J. 'Sniatycki, Ougul Esen","doi":"10.3934/jgm.2020005","DOIUrl":"https://doi.org/10.3934/jgm.2020005","url":null,"abstract":"We show that the De Donder form for second order gravity, defined in terms of Ostrogradski's version of the Legendre transformation applied to all independent variables, is globally defined by its local coordinate descriptions. It is a natural differential operator applied to the diffeomorphism invariant Lagrangian of the theory.","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"230 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75970551","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":"Conservation laws in discrete geometry","authors":"Len G. Margolin, Roy S. Baty","doi":"10.3934/jgm.2019010","DOIUrl":"https://doi.org/10.3934/jgm.2019010","url":null,"abstract":"","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"96 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87888718","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 problem of Lagrange on principal bundles under a subgroup of symmetries","authors":"M. Castrillón López, Pedro Luis García Pérez","doi":"10.3934/jgm.2019026","DOIUrl":"https://doi.org/10.3934/jgm.2019026","url":null,"abstract":"","PeriodicalId":49161,"journal":{"name":"Journal of Geometric Mechanics","volume":"07 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86949579","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}