Positive maps, positive polynomials and entanglement witnesses (2009)
Skowronek, Lukasz, Zyczkowski, Karol
We link the study of positive quantum maps, block positive operators, and entanglement witnesses with problems related to multivariate polynomials. For instance, we show how indecomposable block...
Cones of positive maps and their duality relations (2009)
Skowronek, Lukasz, Stormer, Erling, Zyczkowski, Karol
The structure of cones of positive and k-positive maps acting on a finite-dimensional Hilbert space is investigated. Special emphasis is given to their duality relations to the sets of superpositive...
Chaos in Newtonian iterations: Searching for zeros which are not there (2007)
Skowronek, Lukasz, Gora, P. F.
We show analytically that Newtonian iterations, when applied to a polynomial equation, have a positive topological entropy. In a specific example of an attempt to ``find'' the real solutions of the...