@article {iitisid_0473,
title = {Product numerical range in a space with tensor product structure},
journal = {Linear Algebra Appl.},
volume = {434},
number = {1},
year = {2011},
note = {arXiv:1008.3482 IF=1.005(2010);},
pages = {327{\textendash}342},
abstract = {We study operators acting on a tensor product Hilbert space and investigate their product numerical range, product numerical radius and separable numerical range. Concrete bounds for the product numerical range for Hermitian operators are derived. Product numerical range of a non-Hermitian operator forms a subset of the standard numerical range containing the barycenter of the spectrum. While the latter set is convex, the product range needs not to be convex nor simply connected. The product numerical range of a tensor product is equal to the Minkowski product of numerical ranges of individual factors.},
issn = {0024-3795},
author = {Zbigniew Pucha{\l}a and Piotr Gawron and J.A. Miszczak and {\L}. Skowronek and Man-Duen Choi and Karol {\.Z}yczkowski}
}
@article {iitisid_0476,
title = {Restricted numerical range: A versatile tool in the theory of quantum information},
journal = {J. Math. Phys.},
volume = {51},
number = {10},
year = {2010},
note = {arXiv:0905.3646 IF=1.291(2010);},
pages = {102204},
issn = {00222488},
author = {Piotr Gawron and Zbigniew Pucha{\l}a and J.A. Miszczak and {\L}. Skowronek and Karol {\.Z}yczkowski}
}