作者：Branislav I. Prvulović , Marko Radovanović 来源：[J].Fundamenta Mathematicae(IF 0.529), 2019, Vol.244, pp.167-190IMPAS 摘要：We study the cohomology algebra of the Grassmann manifold $\widetilde G_{k,n}$ of oriented $k$-dimensional subspaces in $\mathbb R^{n+k}$ via the characteristic rank of the canonical vector bundle $\widetilde\gamma_{k,n}$ over $\widetilde G_{k,n}$ (denoted by $\mathrm{charra...  作者：Lionel Darondeau , Piotr Pragacz 来源：[J].Fundamenta Mathematicae(IF 0.529), 2019, Vol.244, pp.191-208IMPAS 摘要：We establish a Gysin formula for Kempf–Laksov flag bundles and we prove a duality theorem for Grassmann bundles. We then combine them to study Schubert bundles, their push-forwards and fundamental classes.  作者：Diana Ojeda-Aristizabal , William Weiss 来源：[J].Fundamenta Mathematicae(IF 0.529), 2019, Vol.244, pp.147-166IMPAS 摘要：Using families of finite sets to represent countable ordinals, we find,for each$k\geq 2$and each$m$with$4\leq m\leq 2k+5\binom{k}{2}$,the least ordinal$\gamma$such that for every$l$we have$\gamma\xrightarrow[\rm top]{} (\omega\cdot 2+1)^2_{l,m}$as topological spaces. We ...  作者：Dmitri Shakhmatov , Víctor Hugo Yañez 来源：[J].Fundamenta Mathematicae(IF 0.529), 2019, Vol.244, pp.125-145IMPAS 摘要：For a subset$A$of a group$G$, we denote by$\def\grp#1{\langle{#1}\rangle}\grp{A}$the smallest subgroup of$G$containing$A$and let$\def\Cyc{\mathrm{Cyc}}\Cyc(A)=\{x\in G:\def\grp#1{\langle{#1}\rangle}\grp{\{x\}}\subseteq A\}$.A topological group$G$is SSGP if$\def\gr...
 作者：Wenfei Xi , Dikran Dikranjan , Wei He ... 来源：[J].Fundamenta Mathematicae(IF 0.529), 2019, Vol.244, pp.109-124IMPAS 摘要：Minimal groups are Hausdorff topological groups $G$ satisfying the open mapping theorem with respect to continuous isomorphisms, i.e., every continuous isomorphism $G\to H$, with $H$ a Hausdorff topological group, is a topological isomorphism. A topological group $(G, \tau )...  作者：M. R. Koushesh 来源：[J].Studia Mathematica(IF 0.549), 2019, Vol.245, pp.33-99IMPAS 摘要：Let$X$be a completely regular topological space. We assign to each (set-theoretic) ideal of$X$an (algebraic) ideal of$C_B(X)$, the normed algebra of continuous bounded scalar-valued mappings on$X$equipped with the supremum norm. We then prove several representation th...  作者：Maria F. Gamal’ 来源：[J].Studia Mathematica(IF 0.549), 2019, Vol.246, pp.133-166IMPAS 摘要：For a power bounded or polynomially bounded operator$T$sufficient conditions for the existence of a nontrivial hyperinvariant subspace are given. These hyperinvariant subspaces are the closures of the range of$\varphi (T)$, where$\varphi $is a singular inner function if$T$...  作者：Raphaël Clouâtre , Laurent W. Marcoux 来源：[J].Studia Mathematica(IF 0.549), 2019, Vol.244, pp.25-41IMPAS 摘要：We examine rigidity phenomena for representations of amenable operator algebras which have an ideal of compact operators. We establish that a generalized version of Kadison’s conjecture on completely bounded homomorphisms holds for the algebra if the associated quotient is a...  作者：Shahar Mendelson , Emanuel Milman , Grigoris Paouris 来源：[J].Studia Mathematica(IF 0.549), 2019, Vol.244, pp.159-202IMPAS 摘要：We propose a program for establishing a conjectural extension to theclass of (origin-symmetric) log-concave probability measures$\mu$, ofthe classical dual Sudakov minoration on the expectation of thesupremum of a Gaussian process:\label{eq:abstract}M\Bigl(Z...  作者：Alex Rice 来源：[J].Acta Arithmetica(IF 0.472), 2019, Vol.187, pp.1-41IMPAS 摘要：We show that if$h\in \mathbb Z[x]$is a polynomial of degree$k\geq 2$such that$h(\mathbb N)$contains a multiple of$q$for every$q\in\mathbb N$, known as an intersective polynomial , then any subset of$\{1,\dots,N\}$with no nonzero differences of the form$h(n)\$ for ...