Zobrazeno 1 - 10
of 274
pro vyhledávání: '"RAVSKY, A."'
Autor:
Firman, Oksana, Kindermann, Philipp, Klemz, Boris, Ravsky, Alexander, Wolff, Alexander, Zink, Johannes
We study the following combinatorial problem. Given a set of $n$ y-monotone \emph{wires}, a \emph{tangle} determines the order of the wires on a number of horizontal \emph{layers} such that the orders of the wires on any two consecutive layers differ
Externí odkaz:
http://arxiv.org/abs/2312.16213
Given items of different sizes and a fixed bin capacity, the bin-packing problem is to pack these items into a minimum number of bins such that the sum of item sizes in a bin does not exceed the capacity. We define a new variant called \emph{$k$-time
Externí odkaz:
http://arxiv.org/abs/2311.16742
A subset $X$ of an Abelian group $G$ is called $midconvex$ if for every $x,y\in X$ the set $\frac{x+y}2=\{z\in G:2z=x+y\}$ is a subset of $X$. We prove that a subset $X$ of an Abelian group $G$ is midconvex if and only if for every $g\in G$ and $x\in
Externí odkaz:
http://arxiv.org/abs/2305.12128
A metric space $(X,d)$ is called a $subline$ if every 3-element subset $T$ of $X$ can be written as $T=\{x,y,z\}$ for some points $x,y,z$ such that $d(x,z)=d(x,y)+d(y,z)$. By a classical result of Menger, every subline of cardinality $\ne 4$ is isome
Externí odkaz:
http://arxiv.org/abs/2305.07907
A subset $X$ of an Abelian group $G$ is called $semiaf\!fine$ if for every $x,y,z\in X$ the set $\{x+y-z,x-y+z\}$ intersects $X$. We prove that a subset $X$ of an Abelian group $G$ is semiaffine if and only if one of the following conditions holds: (
Externí odkaz:
http://arxiv.org/abs/2305.07905
Autor:
Banakh, Taras, Ravsky, Alex
Let $G$ be a paratopological group. Following F. Lin and S. Lin, we say that the group $G$ is pseudobounded, if for any neighborhood $U$ of the identity of $G$, there exists a natural number $n$ such that $U^n=G$. The group $G$ is $\omega$-pseudoboun
Externí odkaz:
http://arxiv.org/abs/2110.02303
Autor:
Banakh, Taras, Ravsky, Alex
Publikováno v:
Bukovin. Mat. Zh. 9:1 (2021), 9-28
Given a topological ring $R$, we study semitopological $R$-modules, construct their completions, Bohr and borno modifications. For every topological space $X$, we construct the free (semi)topological $R$-module over $X$ and prove that for a $k$-space
Externí odkaz:
http://arxiv.org/abs/2104.06713
Autor:
Ravsky, Alex
We consider a recent The Vee's fair soup division problem, provide its partial solution, and pose a related open problem.
Comment: 3 pages
Comment: 3 pages
Externí odkaz:
http://arxiv.org/abs/2102.00309
Autor:
Banakh, Taras, Ravsky, Alex
We define a topological ring $R$ to be \emph{Hirsch}, if for any unconditionally convergent series $\sum_{n\in\omega} x_i$ in $R$ and any neighborhood $U$ of the additive identity $0$ of $R$ there exists a neighborhood $V\subseteq R$ of $0$ such that
Externí odkaz:
http://arxiv.org/abs/2009.09676
A paratopological group $G$ has a {\it suitable set} $S$. The latter means that $S$ is a discrete subspace of $G$, $S\cup \{e\}$ is closed, and the subgroup $\langle S\rangle$ of $G$ generated by $S$ is dense in $G$. Suitable sets in topological grou
Externí odkaz:
http://arxiv.org/abs/2005.08233