Connexions compatibles avec certaines structures sur un fibré vectoriel banachique
Contractibilité du groupe linéaire des espaces de Hilbert de dimension infinie
Contribution of noncommutative geometry to index theory on singular manifolds
This survey of the work of the author with several collaborators presents the way groupoids appear and can be used in index theory. We define the general tools, and apply them to the case of manifolds with corners, ending with a topological index theorem.
Control systems on semi-simple Lie groups and their homogeneous spaces
In the present paper, we consider the class of control systems which are induced by the action of a semi-simple Lie group on a manifold, and we give a sufficient condition which insures that such a system can be steered from any initial state to any final state by an admissible control. The class of systems considered contains, in particular, essentially all the bilinear systems. Our condition is semi-algebraic but unlike the celebrated Kalman criterion for linear systems, it is not necessary. In...
Convergence Rates of the POD–Greedy Method
Iterative approximation algorithms are successfully applied in parametric approximation tasks. In particular, reduced basis methods make use of the so-called Greedy algorithm for approximating solution sets of parametrized partial differential equations. Recently, a priori convergence rate statements for this algorithm have been given (Buffa et al. 2009, Binev et al. 2010). The goal of the current study is the extension to time-dependent problems, which are typically approximated using the POD–Greedy...
Convexity theorem for infinite dimensional isoparametric submanifolds.
Covariantization of quantized calculi over quantum groups
We introduce a method for construction of a covariant differential calculus over a Hopf algebra from a quantized calculus , , where is a candidate for a Dirac operator for . We recover the method of construction of a bicovariant differential calculus given by T. Brzeziński and S. Majid created from a central element of the dual Hopf algebra . We apply this method to the Dirac operator for the quantum given by S. Majid. We find that the differential calculus obtained by our method is the...
Critical point theorems on Finsler manifolds.
Cross-sections of solution funnels in Banach spaces
Curves with finite turn
In this paper we study the notions of finite turn of a curve and finite turn of tangents of a curve. We generalize the theory (previously developed by Alexandrov, Pogorelov, and Reshetnyak) of angular turn in Euclidean spaces to curves with values in arbitrary Banach spaces. In particular, we manage to prove the equality of angular turn and angular turn of tangents in Hilbert spaces. One of the implications was only proved in the finite dimensional context previously, and equivalence of finiteness...
De Rham-Hodge-Kodaira decomposition in ...-dimensions.
Deformation Lemma, Ljusternik-Schnirellmann Theory and Mountain Pass Theorem on C1-Finsler Manifolds
∗Partially supported by Grant MM409/94 Of the Ministy of Science and Education, Bulgaria. ∗∗Partially supported by Grant MM442/94 of the Ministy of Science and Education, Bulgaria.Let M be a complete C1−Finsler manifold without boundary and f : M → R be a locally Lipschitz function. The classical proof of the well known deformation lemma can not be extended in this case because integral lines may not exist. In this paper we establish existence of deformations generalizing the classical result. This...
Densidad de la transversalidad en multijets de variedades con borde anguloso.
Description of infinite-dimensional abelian regular Lie groups.
Determinacy and unipotency.
Diffeology of the infinite Hopf fibration
We introduce diffeological real or complex vector spaces. We define the fine diffeology on any vector space. We equip the vector space 𝓗 of square summable sequences with the fine diffeology. We show that the unit sphere 𝓢 of 𝓗, equipped with the subset diffeology, is an embedded diffeological submanifold modeled on 𝓗. We show that the projective space 𝓟, equipped with the quotient diffeology of 𝓢 by 𝓢¹, is also a diffeological manifold modeled on 𝓗. We define the Fubini-Study symplectic...
Diffeomorphisms between spheres and hyperplanes in infinite-dimensional Banach spaces
Differentiable manifolds with generalized boundary
Differentiable monoids with smooth boundary.
Differentiable semigroups