91 citations · 244 across the 32 of their papers we have counts for
14 papers · 1 filter
Variations on Barbalat's Lemma
Bálint Farkas, Sven-Ake Wegner
It is not hard to prove that a uniformly continuous real function, whose integral up to infinity exists, vanishes at infinity, and it is probably little known that this statement r…
Asymptotics of Evolution Equations beyond Banach spaces
Birgit Jacob, Sven-Ake Wegner
We study the asymptotics of strongly continuous operator semigroups defined on locally convex spaces in order to develop a stability theory for solutions of evolution equations bey…
Desch-Schappacher Perturbation of One-Parameter Semigroups on Locally Convex Spaces
Birgit Jacob, Sven-Ake Wegner, Jens Wintermayr
We prove a Desch-Schappacher type perturbation theorem for strongly continuous and locally equicontinuous one-parameter semigroups which are defined on a sequentially complete loca…
The growth bound for strongly continuous semigroups on Fréchet spaces
Sven-Ake Wegner
We introduce the concepts of growth and spectral bound for strongly continuous semigroups acting on Fréchet spaces and show that the Banach space inequality e…
Asymptotic bounds on the equilateral dimension of hypercubes
Lorenz Minder, Thomas Sauerwald, Sven-Ake Wegner
A subset of the finite dimensional hypercube is said to be equilateral if the distance of any two distinct points equals a fixed value. The equilateral dimension of the hypercube i…
Maximal exact structures on additive categories
Dennis Sieg, Sven-Ake Wegner
We show that every additive category with kernels and cokernels admits a maximal exact structure. Moreover, we discuss two examples of categories of the latter type arising from fu…
Bornological projective limits of inductive limits of normed spaces
José Bonet, Sven-Ake Wegner
We establish a criterion to decide when a countable projective limit of countable inductive limits of normed spaces is bornological. We compare the conditions occurring within our…
Universal extrapolation spaces for C-semigroups
Sven-Ake Wegner
The classical theory of Sobolev towers allows for the construction of an infinite ascending chain of extrapolation spaces and an infinite descending chain of interpolation spaces a…
Projective limits of weighted LB-spaces of holomorphic functions
Sven-Ake Wegner
Countable projective limits of countable inductive limits, called PLB-spaces, of weighted Banach spaces of continuous functions have recently been investigated by Agethen, Biersted…
PLB-spaces of holomorphic functions with logarithmic growth conditions
Sven-Ake Wegner
Countable projective limits of countable inductive limits, called PLB-spaces, of weighted Banach spaces of continuous functions have recently been investigated by Agethen, Biersted…
On the notion of a semi-abelian category in the sense of Palamodov
Yaroslav Kopylov, Sven-Ake Wegner
In the sense of Palamodov, a preabelian category is semi-abelian if for every morphism the natural morphism between the cokernel of its kernel and the kernel of its cokernel is sim…
Exact couples in semiabelian categories revisited
Yaroslav Kopylov, Sven-Ake Wegner
Consider an exact couple in a semiabelian category in the sense of Palamodov, i.e., in an additive category in which every morphism has a kernel as well as a cokernel and the induc…
A short introduction to Gottlob Frege's Begriffsschrift
Sven-Ake Wegner
In his 1879 paper on the Begriffsschrift, Gottlob Frege introduced a notation to formalize mathematical arguments. In this note we explain Frege's notation by using the nowadays co…
Weighted PLB-spaces of continuous functions arising as tensor products of a Fréchet and a DF-space
Sven-Ake Wegner
Countable projective limits of countable inductive limits, so-called PLB-spaces, of weighted Banach spaces of continuous functions have recently been investigated by Agethen, Biers…