activity
20202026
collaborators

11 papers

math.OA2026

Obstructions to the full Hao-Ng isomorphism

Adam Dor-On, Ian Thompson

We show that the Hao-Ng isomorphism for full crossed products fails to hold. More precisely, for a non-degenerate -correspondence over a -algebra and a…

math.CT2025

Local presentability and monadicity of forgetful functors for operator algebraic categories

Alexandru Chirvasitu, Ian Thompson

In recent work of Lindenhovius and Zamdzhiev, it was established that the category of complete operator spaces, with completely contractive linear maps as morphisms, is locally cou…

math.OA2025

Couniversality for C*-algebras of residually finite-dimensional operator algebras

Adam Humeniuk, Christopher Ramsey, Ian Thompson

The C*-envelope of a non self-adjoint operator algebra is known to encode many properties of the underlying subalgebra. However, the C*-envelope does not always encode the residual…

math.OA2025

The Hao-Ng isomorphism theorem for reduced crossed products

Adam Dor-On, Ian Thompson

We prove the Hao-Ng isomorphism for reduced crossed products by locally compact Hausdorff groups. More precisely, for a non-degenerate -correspondence and a gener…

math.OA2024

Rigidity of operator systems: tight extensions and noncommutative measurable structures

Raphaël Clouâtre, Ian Thompson

Let be a unital -algebra generated by some separable operator system . More than a decade ago, Arveson conjectured that is hyperrigid in if all irreducible repr…

math.OA2023

An approximate unique extension property for completely positive maps

Ian Thompson

We study the closure of the unitary orbit of a given point in the non-commutative Choquet boundary of a unital operator space with respect to the topology of pointwise norm converg…

math.NT2023

Jensen polynomials associated with Wright's circle method: Hyperbolicity and Turán inequalities

Jashan Bal, Fern Haraldson, Joshua Males +1

We study the Fourier coefficients of functions satisfying a certain version of Wright's circle method with finitely many major arcs. We show that the Jensen polynomials associated…

math.OA2022

Minimal boundaries for operator algebras

Raphaël Clouâtre, Ian Thompson

We study boundaries for unital operator algebras. These are sets of irreducible -representations that completely capture the spatial norm attainment for a given subalgebra. Clas…

math.GR2022

The number of locally invariant orderings of a group

Idrissa Ba, Adam Clay, Ian Thompson

We show that if a nontrivial group admits a locally invariant ordering, then it admits uncountably many locally invariant orderings. For the case of a left-orderable group, we prov…

math.OA2021

Maximal C^*-covers and residual finite-dimensionality

Ian Thompson

We study residually finite-dimensional (or RFD) operator algebras which may not be self-adjoint. An operator algebra may be RFD while simultaneously possessing completely isometric…

math.OA2020

Finite-dimensionality in the non-commutative Choquet boundary: peaking phenomena and -liminality

Raphaël Clouâtre, Ian Thompson

We explore the finite-dimensional part of the non-commutative Choquet boundary of an operator algebra. In other words, we seek finite-dimensional boundary representations. Such rep…