6 papers · 1 filter
A C*-cover lattice dichotomy
Adam Humeniuk, Christopher Ramsey, Marcel Scherer
In this paper, we show that the lattice of C*-covers of a non-selfadjoint operator algebra is either one point or uncountable. We prove that there are non-selfadjoint operator alge…
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…
An extension property for noncommutative convex sets and duality for operator systems
Adam Humeniuk, Matthew Kennedy, Nicholas Manor
We characterize inclusions of compact noncommutative convex sets with the property that every continuous affine function on the smaller set can be extended to a continuous affine f…
Crossed products and C*-covers of semi-Dirichlet operator algebras
Adam Humeniuk, Elias G. Katsoulis, Christopher Ramsey
In this paper, we show that the semi-Dirichlet C*-covers of a semi-Dirichlet operator algebra form a complete lattice, establishing that there is a maximal semi-Dirichlet C*-cover.…
Jensen's inequality for separately convex noncommutative functions
Adam Humeniuk
Classically, Jensen's Inequality asserts that if is a compact convex set, and is a convex function, then for any probability measure on , that $f(\te…
C*-envelopes of semicrossed products by lattice ordered abelian semigroups
Adam Humeniuk
A semicrossed product is a non-selfadjoint operator algebra encoding the action of a semigroup on an operator or C*-algebra. We prove that, when the positive cone of a discrete lat…