The non-Archimedean Nirgendsnegativsemidefinitheitsstellensatz is not true

Hao Liang, Sizhuo Yan, Jianting Yang +1

Klep and Schweighofer asked whether the Nirgendsnegativsemide-finitheitsstellensatz holds for a symmetric noncommutative polynomial whose evaluations at bounded self-adjoint operat…