On certain random polygons of large areas.
On closed sets with convex projections in Hilbert space
Let k be a fixed natural number. We show that if C is a closed and nonconvex set in Hilbert space such that the closures of the projections onto all k-hyperplanes (planes with codimension k) are convex and proper, then C must contain a closed copy of Hilbert space. In order to prove this result we introduce for convex closed sets B the set consisting of all points of B that are extremal with respect to projections onto k-hyperplanes. We prove that is precisely the intersection of all k-imitations...
On complex -predual spaces.
On Convex Bodies that Permit Packings of High Density.
On Convex Body Chasing.
On convex metric spaces V
On covering of bounded sets by sets with the twice less diameter
On coverings of plane convex sets by translates of strips.
On coverings with convex domains
On criteria of Blumenthal for inner-product spaces
On cross-section measures in Minkowski spaces.
On cyclic α(·)-monotone multifunctions
Let (X,d) be a metric space. Let Φ be a linear family of real-valued functions defined on X. Let be a maximal cyclic α(·)-monotone multifunction with non-empty values. We give a sufficient condition on α(·) and Φ for the following generalization of the Rockafellar theorem to hold. There is a function f on X, weakly Φ-convex with modulus α(·), such that Γ is the weak Φ-subdifferential of f with modulus α(·), .
On deformations of spherical isometric foldings
The behavior of special classes of isometric foldings of the Riemannian sphere under the action of angular conformal deformations is considered. It is shown that within these classes any isometric folding is continuously deformable into the standard spherical isometric folding defined by .
On differentiability of strongly α(·)-paraconvex functions in non-separable Asplund spaces
In Rolewicz (2002) it was proved that every strongly α(·)-paraconvex function defined on an open convex set in a separable Asplund space is Fréchet differentiable on a residual set. In this paper it is shown that the assumption of separability is not essential.
On exposed points and extremal points of convex sets in ℝⁿ and Hilbert space
Let be a Euclidean space or the Hilbert space ℓ², let k ∈ ℕ with k < dim , and let B be convex and closed in . Let be a collection of linear k-subspaces of . A set C ⊂ is called a -imitation of B if B and C have identical orthogonal projections along every P ∈ . An extremal point of B with respect to the projections under is a point that all closed subsets of B that are -imitations of B have in common. A point x of B is called exposed by if there is a P ∈ such that (x+P) ∩ B = x. In the present...
On extremal solutions of martingale problems
On face vectors of trivalent maps
On faces of a convex polyhedron in with a small number of sides.
On face-vectors and vertex-vectors of polyhedral maps on orientable -manifolds
On finite sphere-packings.