N. Szakács

activity

20222025

collaborators

3 papers

math.OA2025

Algebraic singular functions are not always dense in the ideal of $C^{*}$ -singular functions

Diego Martínez, Nóra Szakács

We give the first examples of étale (non-Hausdorff) groupoids $G$ whose $C^{*}$ -algebras contain singular elements that cannot be approximated by singular elements in $\math…

math.GR2023

$E$ -unitary and $F$ -inverse monoids, and closure operators on group Cayley graphs

Nóra Szakács

We show that the category of $X$ -generated $E$ -unitary inverse monoids with greatest group image $G$ is equivalent to the category of $G$ -invariant, finitary closure operators on t…

math.OA2022

Quasi-countable inverse semigroups as metric spaces, and the uniform Roe algebras of locally finite inverse semigroups

Yeong Chyuan Chung, Diego Martínez, Nóra Szakács

Given any quasi-countable, in particular any countable inverse semigroup $S$ , we introduce a way to equip $S$ with a proper and right subinvariant extended metric. This generalizes…

Algebraic singular functions are not always dense in the ideal of C∗-singular functions

E-unitary and F-inverse monoids, and closure operators on group Cayley graphs

Quasi-countable inverse semigroups as metric spaces, and the uniform Roe algebras of locally finite inverse semigroups

Algebraic singular functions are not always dense in the ideal of $C^{*}$ -singular functions

$E$ -unitary and $F$ -inverse monoids, and closure operators on group Cayley graphs