00829nas a2200121   4500000000100000008004100001100002100042700002400063700001900087245006000106856003700166520050400203       2020                            d1 aRyszard Kukulski1 aPaulina Lewandowska1 aŁukasz Pawela00aPerturbation of the numerical range of unitary matrices  uhttps://arxiv.org/abs/2002.055533 a<p>In this work we show how to approach the problem of manimulating the numerical range of a unitary matrix. This task has farreaching impact on the study of discrimination of quantum measurements. We achieve the aforementioned manipulation by introducing<br />
a method which allows us to find a unitary matrix whose numerical range contains the origin where at the same time the distance between<br />
unitary matrix and its perturbation is relative small in given metric.</p>

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