作者：Zhenghua Luo , Bentuo Zheng 来源：[J].Studia Mathematica(IF 0.549), 2020, Vol.250, pp.19-34IMPAS 摘要：A normed space $X$ is said to have the ball-covering property (BCP,for short) if its unit sphere can be covered by the union of countablymany closed balls not containing the origin. Let $(\varOmega, \varSigma, \mu)$ bea separable measure space and $X$ be a normed space. We show t...
 作者：Paweł Domański , Lech Drewnowski 来源：[J].Studia Mathematica(IF 0.549), 2020, Vol.250, pp.57-107IMPAS 摘要：Various Banach or Fréchet spaces which are either vector-valued sequence spaces or components of some closed operator ideals are considered. Complete solutions are given to the problem of their injectivity or embeddability as complemented subspaces in dual Fréchet spaces. Th...
 作者：Monia Mestiri 来源：[J].Studia Mathematica(IF 0.549), 2020, Vol.250, pp.1-18IMPAS 摘要：Considering a family of upper frequently hypercyclic operators we study the existence of vectors which are upper frequently hypercyclic for any operator of this family. We establish sufficient conditions for an uncountable family of operators to admit such vectors called common u...
 作者：Jafar Soltani Farsani 来源：[J].Studia Mathematica(IF 0.549), 2020, Vol.250, pp.35-55IMPAS 摘要：We study the hyperreflexivity of the bounded $n$-cocycle spaces of Banach algebras with matrix representations. We show how representing elements of a Banach algebra as matrices helps us to prove that the Banach algebra has the strong property $(\mathbb {B})$ with a constant. Con...
 作者：Shane Chern , Dazhao Tang , Liuquan Wang 来源：[J].Acta Arithmetica(IF 0.472), 2019, Vol.190, pp.171-191IMPAS 摘要：In order to provide a unified combinatorial interpretation of congruences modulo $5$ for 2-colored partition functions, Garvan introduced a bicrank statistic in terms of weighted vector partitions. In this paper, we obtain some inequalities between the bicrank counts $M^{*}(...  作者：Eleni Agathocleous 来源：[J].Acta Arithmetica(IF 0.472), 2019, Vol.190, pp.305-315IMPAS 摘要：We study the structure of the$3$-part of the ideal class group of a certain family of real cyclotomic fields with$3$-class number exactly$9$and conductor equal to the product of two distinct odd primes. We employ known results from class field theory as well as theoretical an...  作者：Michael Filaseta , Robert Murphy , Andrew Vincent 来源：[J].Banach Center Publications, 2019, Vol.118, pp.245-259IMPAS 摘要：Let$f(x)$be a polynomial with integer coefficients.If either$f(x) = x^{{\rm deg}\,{f}}f(1/x)$or$f(x) = -x^{{\rm deg}\,{f}}f(1/x)$, then$f(x)$is called reciprocal.We refer to the non-reciprocal part of$f(x)$as the polynomial$f(x)$removedof each of its irreducible recipr...  作者：Ignacio Vergara 来源：[J].Studia Mathematica(IF 0.549), 2019, Vol.249, pp.59-109IMPAS 摘要：We give a characterisation of radial Schur multipliers on finite products of trees. The equivalent condition is that a certain generalised Hankel matrix involving the discrete derivatives of the radial function is a trace class operator. This extends Haagerup, Steenstrup and...  作者：Paul F. X. Müller , Peter Yuditskii 来源：[J].Colloquium Mathematicum(IF 0.403), 2019, Vol.158, pp.141-155IMPAS 摘要：The real and complex interpolation spaces for the classical Hardy spaces$H^1$and$H^\infty$were determined in 1983 by P. W. Jones. Due to the analytic constraints the associated Marcinkiewicz decomposition gives rise to a delicate approximation problem for the$L^ 1$metric.Sp...  作者：Konstantin Slutsky 来源：[J].Fundamenta Mathematicae(IF 0.529), 2019, Vol.247, pp.1-24IMPAS 摘要：This paper addresses the notion of time change equivalence for Borel$ \mathbb {R}^{d} $-flows. We show that all free non-smooth$ \mathbb {R}^{d} \$-flows are time change equivalent up to a compressible set. An appropriate version of this result for non-free flows is also given.