45 citations · 156 across the 15 of their papers we have counts for
15 papers · 1 filter
The Polynomial Endomorphisms of Graph Algebras
Rune Johansen, Adam P. W. Sørensen, Wojciech Szymański
We investigate polynomial endomorphisms of graph -algebras and Leavitt path algebras. To this end, we define and analyze the coding graph corresponding to each such an endomor…
C*-stability of discrete groups
Søren Eilers, Tatiana Shulman, Adam P. W. Sørensen
A group may be considered -stable if almost representations of the group in a -algebra are always close to actual representations. We initiate a systematic study of which…
The complete classification of unital graph -algebras: Geometric and strong
Søren Eilers, Gunnar Restorff, Efren Ruiz +1
We provide a complete classification of the class of unital graph -algebras - prominently containing the full family of Cuntz-Krieger algebras - showing that Morita equivalenc…
Geometric classification of graph -algebras over finite graphs
Søren Eilers, Gunnar Restorff, Efren Ruiz +1
We address the classification problem for graph -algebras of finite graphs (finitely many edges and vertices), containing the class of Cuntz-Krieger algebras as a prominent sp…
Invariance of the Cuntz splice
Søren Eilers, Gunnar Restorff, Efren Ruiz +1
We show that the Cuntz splice induces stably isomorphic graph -algebras.
Geometric classification of unital graph C*-algebras of real rank zero
Søren Eilers, Gunnar Restorff, Efren Ruiz +1
We generalize the classification result of Restorff on Cuntz-Krieger algebras to cover all unital graph C*-algebras with real rank zero, showing that Morita equivalence in this cas…
UCT-Kirchberg algebras have nuclear dimension one
Efren Ruiz, Aidan Sims, Adam P. W. Sørensen
We prove that every Kirchberg algebra in the UCT class has nuclear dimension 1. We first show that Kirchberg 2-graph algebras with trivial and finite have nuclear dimen…
Semiprojectivity with and without a group action
N. Christopher Phillips, Adam P. W. Sørensen, Hannes Thiel
The equivariant version of semiprojectivity was recently introduced by the first author. We study properties of this notion, in particular its relation to ordinary semiprojectivity…
Almost Commuting Orthogonal Matrices
Terry A. Loring, Adam P. W. Sørensen
We show that almost commuting real orthogonal matrices are uniformly close to exactly commuting real orthogonal matrices. We prove the same for symplectic unitary matrices. This is…
On a counterexample to a conjecture by Blackadar
Adam P. W. Sørensen
Blackadar conjectured that if we have a split short-exact sequence 0 -> I -> A -> A/I -> 0 where I is semiprojective and A/I is isomorphic to the complex numbers, then A must be se…
Geometric classification of simple graph algebras
Adam P. W. Sørensen
Inspired by Franks' classification of irreducible shifts of finite type we provide a short list of allowed moves on graphs that preserves the stable isomorphism class of the associ…
Amplified graph C*-algebras
Søren Eilers, Efren Ruiz, Adam P. W. Sørensen
We provide a complete invariant for graph C*-algebras which are amplified in the sense that whenever there is an edge between two vertices, there are infinitely many. The invariant…
Almost commuting unitary matrices related to time reversal
Terry A. Loring, Adam P. W. Sørensen
The behavior of fermionic systems depends on the geometry of the system and the symmetry class of the Hamiltonian and observables. Almost commuting matrices arise from band-project…
A characterization of semiprojectivity for commutative C*-algebras
Adam P. W. Sørensen, Hannes Thiel
Given a compact, metric space X, we show that the commutative C*-algebra C(X) is semiprojective if and only if X is an absolute neighborhood retract of dimension at most one. This…
Almost commuting self-adjoint matrices --- the real and self-dual cases
Terry A. Loring, Adam P. W. Sørensen
We show that a pair of almost commuting self-adjoint, symmetric matrices is close to a pair of commuting self-adjoint, symmetric matrices (in a uniform way). Moreover we prove that…