Entanglement in the Dicke subspace https://arxiv.org/pdf/2602.15800 Aabhas Gulati, Ion Nechita, Clément Pellegrini.

Projections with Respect to Bures Distance and Fidelity: Closed-Forms and Applications https://arxiv.org/pdf/2602.14732 A. Afham, Marco Tomamichel.

New preprint out with @marcotomamichel.bsky.social ! Projections with Respect to Bures Distance and Fidelity: Closed-Forms and Applications scirate.com/arxiv/2602.1... We derive simple closed-form solutions for fidelity / Bures/purified distance projections to various sets of interest.

Q: Let X be a (non-Hermitian) matrix with positive eigenvalues (such X = AB, where A,B >= 0) and let Λ be a Completely positive map. Is Λ(X) guaranteed to be a matrix with positive eigenvalues? That is, do CP maps take EVERY (including non-Herm) matrix with pos evals to matrices with pos evals?