Results 31 to 40 of about 20,498 (195)
Communications in Mathematical Physics, 2000 The basic mathematical framework for super Hilbert spaces over a Grassmann algebra with a Grassmann number-valued inner product is formulated. Super Hilbert spaces over infinitely generated Grassmann algebras arise in the functional Schroedinger representation of spinor quantum field theory in a natural way.
openaire +4 more sources
A characterization of Hilbert space [PDF]
Proceedings of the American Mathematical Society, 1974 A real Banach space E of dimension _3 is an inner product space iff there exists a bounded smooth convex subset of E which is the range of a nonexpansive retraction. De Figueiredo and Karlovitz [3] have shown that if E is a strictly convex real finite-dimensional Banach space and dim E> 3 then there can exist no bounded smooth nonexpansive retract of E
openaire +2 more sources
Topological Transitivity of Shift Similar Operators on Nonseparable Hilbert Spaces
Journal of Function Spaces, 2021 In this paper, we investigate topological transitivity of operators on nonseparable Hilbert spaces which are similar to backward weighted shifts.
Andriy Zagorodnyuk, Zoriana Novosad
doaj +1 more source
A WEAK HILBERT SPACE THAT IS A TWISTED HILBERT SPACE
Journal of the Institute of Mathematics of Jussieu, 2018 We construct a weak Hilbert space that is a twisted Hilbert space.
openaire +3 more sources
Mathematische Zeitschrift, 1992 The paper presents some results and a list of examples concerning the structure of subgroups \(\Gamma\) (with respect to addition) of a Hilbert space \(H\), especially their topological dimension \(ind\) and fundamental sets, i.e. closed and convex subsets \(K\) of \(H\) such that \(\pi(K)=H/\Gamma\) and \(\pi_{\mid\text{rint}(K)}\) is a homeomorphism ...
Dobrowski, Tadeusz, Grabowski, Janusz
openaire +2 more sources
Convexity and the Euclidean Metric of Space-Time
Universe, 2017 We address the reasons why the “Wick-rotated”, positive-definite, space-time metric obeys the Pythagorean theorem. An answer is proposed based on the convexity and smoothness properties of the functional spaces purporting to provide the kinematic ...
Nikolaos Kalogeropoulos
doaj +1 more source
The Split Various Variational Inequalities Problems for Three Hilbert Spaces
Axioms, 2020 There are many methods for finding a common solution of a system of variational inequalities, a split equilibrium problem, and a hierarchical fixed-point problem in the setting of real Hilbert spaces. They proved the strong convergence theorem.
Chinda Chaichuay, Atid Kangtunyakarn
doaj +1 more source
On the definition of Hilbert space
Manuscripta Mathematica, 1977 The projection theorem expresses a central feature of classical Hilbert space. Do other infinite dimensional sesquilinear spaces share this property? We show here that this is not the case for several prominent candidates; in particular Kalish's p-adic Hilbert spaces, Springers non archimedean normed spaces, the positive definite spaces over ordered ...
Gross, Herbert, Keller, Hans A.
openaire +3 more sources
On convolutions in Hilbert spaces [PDF]
Functional Analysis and Its Applications, 2017 A convolution in a Hilbert space is defined, and its basic properties are studied.
Michael Ruzhansky +3 more
openaire +5 more sources
On a Generalization of the Hilbert Frame Generated by the Bilinear Mapping
Journal of Function Spaces, 2016 The concept of b-frame which is a generalization of the frame in Hilbert spaces generated by the bilinear mapping is considered. b-frame operator is defined; analogues of some well-known results of frame theory are obtained in Hilbert spaces.
Migdad Ismailov +2 more
doaj +1 more source