6 papers · 1 filter
Semiprime ideals in C*-algebras
Eusebio Gardella, Kan Kitamura, Hannes Thiel
We show that a not necessarily closed ideal in a C*-algebra is semiprime if and only if it is idempotent, if and only if it is closed under square roots of positive elements. Among…
Actions on classifiable C*-algebras without equivariant property (SI)
Eusebio Gardella, Julian Kranz, Andrea Vaccaro
We exhibit examples of actions of countable discrete groups on both simple and non-simple nuclear stably finite C*-algebras that are tracially amenable but not amenable. We further…
Rigidity results for -operator algebras and applications
Yemon Choi, Eusebio Gardella, Hannes Thiel
For , we show that every unital -operator algebra contains a unique maximal -subalgebra, which is always abelian if . Using this, we canonically…
Essential freeness, allostery and -stability of crossed products
Eusebio Gardella, Shirly Geffen, Rafaela Gesing +2
We explore classifiability of crossed products of actions of countable amenable groups on compact, metrizable spaces. It is completely understood when such crossed products are sim…
Products of commutators in matrix rings
Matej Brešar, Eusebio Gardella, Hannes Thiel
Let be a ring and let . We discuss the question of whether every element in the matrix ring is a product of (additive) commutators , for $x,y\in M…
Generalisations of Thompson's group V arising from purely infinite groupoids
Eusebio Gardella, Owen Tanner
We study a class of generalisations of Thompson's group arising naturally as topological full groups of purely infinite, minimal groupoids. In the process, we show that the der…