Results 11 to 20 of about 3,277 (79)
Best approximation in polyhedral Banach spaces
Journal of Approximation Theory, 2011 The authors study conditions under which the metric projection of a polyhedral Banach space \(X\) onto a closed subspace \(Y\) is Hausdorff lower or upper semicontinuous. The paper is organized as follows. Section 0 is an introduction. Section 1 contains notation concerning Banach spaces, followed by definitions and preliminary facts on polyhedral ...
V. P. Fonf, J. Lindenstrauss, L. Vesely
openaire +3 more sources
Polyhedral norms on non-separable Banach spaces
Journal of Functional Analysis, 2008 A Banach space \(X\) is called polyhedral if the unit ball of each of its finite-dimensional subspaces is a polytope. Separable polyhedral spaces were investigated in detail; see, e.g., [\textit{V. P. Fonf, J.\,Lindenstrauss} and \textit{R. P. Phelps}, in: Handbook of the Geometry of Banach spaces, Vol.\ I, Elsevier, 599--670 (2001; Zbl 1086.46004 ...
Fonf, V.P. +3 more
openaire +3 more sources
Extension of isometries between unit spheres of finite-dimensional polyhedral Banach spaces
Journal of Mathematical Analysis and Applications, 2012 We prove that an onto isometry between unit spheres of finite-dimensional polyhedral Banach spaces extends to a linear isometry of the corresponding spaces.
Kadets, Vladimir, Martín, Miguel
openaire +5 more sources
Polyhedral direct sums of Banach spaces, and generalized centers of finite sets
Journal of Mathematical Analysis and Applications, 2012 Let \(X\) be a real Banach space. \(X\) is said to satisfy \((GC)\) if for every \(n\) and for every real-valued continuous, nondecreasing coercive function \(f\) on \( [0,\infty)^n\), the set \(E_f(a)\) of minimizers of the function \(\phi(x) = f(\|x-a_1\|,\dots,\|x-a_n\|)\) is nonempty, where \(x \in X\) and \(a= (a_1,\dots,a_n) \in X^n\).
Libor Vesely
openaire +3 more sources
Mathematische Nachrichten, Volume 296, Issue 3, Page 1135-1155, March 2023., 2023 Abstract In this study, we consider the Oseen structure of the linearization of a compressible fluid–structure interaction (FSI) system for which the interaction interface is under the effect of material derivative term. The flow linearization is taken with respect to an arbitrary, variable ambient vector field.
Pelin G. Geredeli
wiley +1 more source
Nonlocal homogenisation theory for curl‐div‐systems
Mathematische Nachrichten, Volume 295, Issue 5, Page 950-969, May 2022., 2022 Abstract We study the curl‐div‐system with variable coefficients and a nonlocal homogenisation problem associated with it. Using, in part refining, techniques from nonlocal H‐convergence for closed Hilbert complexes, we define the appropriate topology for possibly nonlocal and non‐periodic coefficients in curl‐div systems to model highly oscillatory ...
Serge Nicaise, Marcus Waurick
wiley +1 more source
Div–curl problems and H1‐regular stream functions in 3D Lipschitz domains
Mathematical Methods in the Applied Sciences, Volume 45, Issue 3, Page 1097-1117, February 2022., 2022 We consider the problem of recovering the divergence‐free velocity field U ∈ L2(Ω) of a given vorticity F=curlU on a bounded Lipschitz domain Ω⊂ℝ3. To that end, we solve the ‘div–curl problem’ for a given F ∈ H−1(Ω). The solution is expressed in terms of a vector potential (or stream function) A ∈ H1(Ω) such that U=curlA. After discussing existence and
Matthias Kirchhart, Erick Schulz
wiley +1 more source
Mobile Information Systems, Volume 2022, Issue 1, 2022., 2022 Due to the influence of many factors such as machining and working environment, the robot kinematics model has errors, which leads to the inaccuracy of the actual position and pose. Therefore, in order to solve this problem, this paper proposes a method based on the genetic algorithm to directly modify the rotation variables of the manipulator joint to
Li Zhang, Hye-jin Kim
wiley +1 more source
Almost uniform domains and Poincaré inequalities
Transactions of the London Mathematical Society, Volume 8, Issue 1, Page 243-298, December 2021., 2021 Abstract Here we show existence of many subsets of Euclidean spaces that, despite having empty interior, still support Poincaré inequalities with respect to the restricted Lebesgue measure. Most importantly, despite the explicit constructions in our proofs, our methods do not depend on any rectilinear or self‐similar structure of the underlying space ...
Sylvester Eriksson‐Bique, Jasun Gong
wiley +1 more source
Dold sequences, periodic points, and dynamics
Bulletin of the London Mathematical Society, Volume 53, Issue 5, Page 1263-1298, October 2021., 2021 Abstract In this survey we describe how the so‐called Dold congruence arises in topology, and how it relates to periodic point counting in dynamical systems.
Jakub Byszewski +2 more
wiley +1 more source