Recherche |
Abstract: This book describes in detail the basic context of the Banach setting and the most important Lie structures found in finite dimension. The authors expose these concepts in the convenient framework which is a common context for projective and direct limits of Banach structures. The book presents sufficient conditions under which these structures exist by passing to such limits. In fact, such limits appear naturally in many mathematical and physical domains. Many examples in various fields illustrate the different concepts introduced.
Many geometric structures, existing in the Banach setting, are "stable" by passing to projective and direct limits with adequate conditions. The convenient framework is used as a common context for such types of limits. The contents of this book can be considered as an introduction to differential geometry in infinite dimension but also a way for new research topics.
This book allows the intended audience to understand the extension to the Banach framework of various topics in finite dimensional differential geometry and, moreover, the properties preserved by passing to projective and direct limits of such structures as a tool in different fields of research.
Abstract: In this paper the notion of Dirac structure in finite dimension is extended to the convenient setting. In particular, we introduce the notion of partial Dirac structure on convenient Lie algebroids and manifolds. We then look for those structures whose classical geometrical results in finite dimension can be extended to this infinite dimensional context. Finally, we are interested in the projective and direct limits of such structures.
Résumé : Nous introduisons dans cet article trois notions de structures bihamiltoniennes partielles ($\operatorname{PQ}$, $\operatorname{PN}$ et $\operatorname{P\Omega}$) dans le cadre $c^\infty$-complet au sens de Frölicher, Kriegl et Michor (ou cadre adapté), étudions des objets géométriques liés à ces structures et en donnons des exemples à la fois en dimensions finie et infinie.
Abstract: We introduce three notions of partial bihamiltonian structures ($\operatorname{PQ}$, $\operatorname{PN}$ et $\operatorname{P\Omega}$) in the convenient setting defined by Frölicher, Kriegl and Michor. We study geometrical objects linked with these structures and give examples in finite and infinite dimensions.
Abstract: This paper offers an adaptation to the convenient setting of finite dimensional Nambu-Poisson structures. In particular, for partial Nambu structures, we look for those whose classical geometrical results in finite dimension can be extended to this infinite dimensional context. Finally, we are interested in the projective and direct limits of such structures.
Abstract: We first define the concept of Lie algebroid in the convenient setting. In reference to the finite dimensional context, we adapt the notion of prolongation of a Lie algebroid over a fibred manifold to a convenient Lie algebroid over a fibred manifold. Then we show that this construction is stable under projective and direct limits under adequate assumptions.
Abstract: We endow projective (resp. direct) limits of Banach tensor structures with Fr\'{e}chet (resp. convenient) structures and study adapted connections to $G$-structures in both frameworks. This situation is illustrated by a lot of examples.
Abstract: This paper is devoted to the framework of direct limit of anchored Banach bundles over a convenient manifold which is a direct limit of manifolds. In particular we give a criterion of integrability for distributions on such convenient manifolds which are locally direct limits of particular sequences of Banach anchor ranges.
Résumé : Dans cet article, on s'intéresse à l'étude de divers objets rencontrés dans le cadre de limites directes de fibrés de Banach, munis d'une ancre, au dessus de certaines variétés apparaissant comme limites directes de variétés de Banach. En particulier, on donne un critère d'intégrabilité pour des distributions sur de telles variétés qui sont localement des limites directes de suites particulières d'images d'ancres banachiques.
Abstract: We define the notion of projective limit of local shift morphisms of type $\left( r,s\right) $ and endow the space of such mathematical objects with an adapted differential structure. The notion of shift Poisson tensor $P$ on a Hilbert tower corresponds to such a morphism which is antisymmetric and whose Schouten bracket with itself $\left[ P,P\right] $ vanishes. We illustrate this notion with the example of the famous KdV equation on the circle $\mathbb{S}^{1}$ for which one can associate a pair of such compatible Poisson tensors on the Hilbert tower $\left( H^{n} \left( \mathbb{S}^{1} \right)\right) _{n\in\mathbb{N}^{\ast}}$.
Abstract: We introduce the concept of partial Poisson structure on a manifold M modelled on a convenient space. This is done by specifying a (weak) subbundle $T^{\prime}M$ of $T^{\ast}M$ and an antisymmetric morphism $:T^{\prime}M \rightarrow TM$ such that the bracket defines a Poisson bracket on the algebra $\mathcal{A}$ of smooth functions $f$ on $M$ whose differential $df$ induces a section of $T^{\prime}M$. In particular, to each such function $f\in\mathcal{A}$ is associated a hamiltonian vector field $P(df)$. This notion takes naturally place in the framework of infinite dimensional weak symplectic manifolds and Lie algebroids. After having defined this concept, we will illustrate it by a lot of natural examples. We will also consider the particular situations of direct (resp. projective) limits of such Banach structures. Finally, we will also give some results on the existence of (weak) symplectic foliations naturally associated to some particular partial Poisson structures.
Abstract: We prove that direct limits of finite dimensional Lie algebroids and their prolongations can be endowed with structures of convenient spaces.
Resumen: Probamos que se puede definir estructuras de espacios convenientes
sobre límites directos de algebroides de Lie y sus prolongaciones.
Resumé : On établit que l’on peut munir les limites directes d’algébroïdes de
Lie et de leurs prolongements de structures d’espaces $c^\infty$-complets (adapté).
Abstract: We equip the direct limit of tangent bundles of paracompact finite dimensional manifolds with a structure of convenient vector bundle.
Abstract: Under appropriate assumptions, we generalize the concept of linear almost Poisson structures, almost Lie algebroids, almost differentials in the framework of Banach anchored bundles and the relation between these objects. We then obtain an adapted formalism for mechanical systems which is illustrated by the evolutionary problem of the "Hilbert snake".
Abstract: We define the notion of strong projective limit of Banach Lie algebroids. We study the associated structures of Fréchet bundles and the compatibility with the different morphisms. This kind of structure seems to be a convenient framework for various situations.
Résumé : On définit la notion de limite projective forte d'algébroïdes de Lie banachiques. On étudie les structures associées de fibrés fréchétiques et la compatibilité avec les divers morphismes. Ce type de structure semble être un cadre adapté pour des situations variées.
Abstract: We build a stratification on the $1$-jets of pairs (vector fields, twice contravariant tensors) which allows to define the notion of finite-dimensional generic Jacobi manifold. We then describe the singularities of the associated characteristic field. We also give an example of such manifolds in thermodynamics.
Abstract: The notion of generalized PN manifold is a framework which allows to get properties about first integrals of the associated bihamiltonian system: conditions of existence of a bi-abelian sub-algebra obtained from the momentum map and characterization of such an algebra linked with the problem ofseparation of variables.
Abstract: We define the notion of bilagrangian fanning curves on $\mathbb{R}^{2n}$ endowed with a $\omega N$ structure; these curves are lagrangian and invariant with respect to the recursion operator $N.$We study some of their properties of and give an example of these curves in mechanics.