6 papers
Positive definite matrices and involutions: the manners of their infinite cousins
Pere Ara, Ken Goodearl, Kevin C. O'Meara
Matrices and involutions in/on the algebras and of real (resp., complex) row- and column-finite matrices are studied. It is proved that a…
Poisson fields of two variables
Ken Goodearl, James J. Zhang
We study invariants and structures of Poisson fields of rational functions in two variables. For four particular families, we classify the members, establish criteria for isomorphi…
Skew fields not finitely generated as algebras
K. R. Goodearl, E. S. Letzter
An associative division algebra D is said to be _affine_ over a central subfield k if D is finitely generated as a k-algebra. In 1956 Amitsur famously proved that, when k is uncoun…
Levels of cancellation for monoids and modules
Pere Ara, Ken Goodearl, Pace P. Nielsen +3
Levels of cancellativity in commutative monoids , determined by stable rank values in for elements of , are investigated. The behavior of t…
Regular Ring Properties Degraded Through Inverse Limits
Pere Ara, Ken Goodearl, Kevin C. O'Meara +2
We give a number of constructions where inverse limits seriously degrade properties of regular rings, such as unit-regularity, diagonalisation of matrices, and finite stable rank.…
The separativity problem in terms of varieties and diagonal reduction
Pere Ara, Ken Goodearl, Pace P. Nielsen +2
We provide two new formulations of the separativity problem. First, it is known that separativity (and strong separativity) in von Neumann regular (and exchange) rings is tightly c…