O některých Banachových problémech
On a generalized -inner product and the corresponding Cauchy-Schwarz inequality.
On a lattice characterization of Hilbert spaces
On a superadditivity property of Gram's determinant.
On certain trigonometric sums in several variables.
On coarse embeddability into -spaces and a conjecture of Dranishnikov
We show that the Hilbert space is coarsely embeddable into any for 1 ≤ p ≤ ∞. It follows that coarse embeddability into ℓ₂ and into are equivalent for 1 ≤ p < 2.
On complete-cocomplete subspaces of an inner product space
In this note we give a measure-theoretic criterion for the completeness of an inner product space. We show that an inner product space is complete if and only if there exists a -additive state on , the orthomodular poset of complete-cocomplete subspaces of . We then consider the problem of whether every state on , the class of splitting subspaces of , can be extended to a Hilbertian state on ; we show that for the dense hyperplane (of a separable Hilbert space) constructed by P. Pták and...
On criteria of Blumenthal for inner-product spaces
On generalizations of Grüss inequality in inner product spaces and applications.
On orbits for pairs of operators on an infinite-dimensional complex Hilbert space
On reverses of some inequalities in -inner product spaces.
On semi-inner product spaces, I
On solvability of fourth order operator-diferential equations of elliptic type on weight spaces.
On some global and local geometric properties of Calderón-Lozanovskiĭ spaces
Criteria for full k-rotundity (k ∈ ℕ, k ≥ 2) and uniform rotundity in every direction of Calderón-Lozanovskiĭ spaces are formulated. A characterization of -points in these spaces is also given.
On some properties of Banach operators.
On some properties of Banach operators. II.
On strictly convex and strictly 2-convex 2-normed spaces. II.
On the angles between certain arithmetically defined subspaces of
If and are two families of unitary bases for , and is a fixed number, let and be subspaces of spanned by vectors in and respectively. We study the angle between and as goes to infinity. We show that when and arise in certain arithmetically defined families, the angles between and may either tend to or be bounded away from zero, depending on the behavior of an associated eigenvalue problem.
On the characterization of weak closure in Hilbert space
On the closure of the sum of closed subspaces.