64 citations · 85 across the 5 of their papers we have counts for
7 papers
The Fréchet derivative is in the first Baire class
Eva Kopecká, Luděk Zaj\'ıček
Let be a normed linear space, a Banach space, an open set and a mapping. We show that the Fréchet derivative of is of the first Baire clas…
Weak limits of consecutive projections and of greedy steps
Petr A. Borodin, Eva Kopecka
Let be a Hilbert space. We investigate the properties of weak limit points of iterates of random projections onto closed convex sets in and the parallel propertie…
When products of projections diverge
Eva Kopecka
Slow convergence of cyclic projections implies divergence of random projections and vice versa. Let be a family of closed subspaces of a Hilbert space. It i…
Mapping grid points onto a square forces an arbitrarily large Lipschitz constant
Michael Dymond, Vojtěch Kaluža, Eva Kopecká
We prove that the regular square grid of points in the integer lattice cannot be recovered from an arbitrary -element subset of …
A note on alternating projections in Hilbert space
Eva Kopecka, Simeon Reich
We provide a direct proof of a result regarding the asymptotic behavior of alternating nearest point projections onto two closed and convex sets in a Hilbert space. Our arguments a…
Strange products of projections
Eva Kopecká, Adam Paszkiewicz
Let be an infinite dimensional Hilbert space. We show that there exist three orthogonal projections onto closed subspaces of such that for every $0\ne z_0\i…
Zone diagrams in compact subsets of uniformly convex normed spaces
Eva Kopecká, Daniel Reem, Simeon Reich
A zone diagram is a relatively new concept which has emerged in computational geometry and is related to Voronoi diagrams. Formally, it is a fixed point of a certain mapping, and n…