37 citations · 78 across the 9 of their papers we have counts for
10 papers
Real Schur norms and Hadamard matrices
John Holbrook, Nathaniel Johnston, Jean-Pierre Schoch
We present a preliminary study of Schur norms , where M is a matrix whose entries are , and denotes the entrywise (i.e., Sch…
A computing strategy and programs to resolve the Gerstenhaber Problem for commuting triples of matrices
John Holbrook, Kevin C. O'Meara
We describe a MATLAB program that could produce a negative answer to the Gerstenhaber Problem by the construction of three commuting matrices over a field …
Normal matrix compressions
John Holbrook, Nishan Mudalige, Rajesh Pereira
The recently developed theory of higher--rank numerical ranges originated in problems of error correction in quantum information theory but its mathematical implications now includ…
Restricted numerical shadow and geometry of quantum entanglement
Zbigniew Puchała, Jarosław Adam Miszczak, Piotr Gawron +3
The restricted numerical range of an operator acting on a -dimensional Hilbert space is defined as a set of all possible expectation values of this operator among p…
Numerical shadow and geometry of quantum states
Charles F. Dunkl, Piotr Gawron, John A. Holbrook +3
The totality of normalised density matrices of order N forms a convex set Q_N in R^(N^2-1). Working with the flat geometry induced by the Hilbert-Schmidt distance we consider image…
Numerical shadows: measures and densities on the numerical range
Charles F. Dunkl, Piotr Gawron, John A. Holbrook +2
For any operator acting on an -dimensional Hilbert space we introduce its numerical shadow, which is a probability measure on the complex plane supported by the numeri…