In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

In quantum mechanics, Koopmans theorem can be used to provide an interpretation of these, with regard to a Fock operator, as ionization potentials. If an operator is Hermitian, these are real, and the set of these is referred to as an operator's spectrum. The determinant of a finite matrix is equal to the product of these, and the sum of these is equal to its trace. FTP, name these roots of a matrixs characteristic equation that are defined as the solutions of the characteristic polynomial of a matrix.
Science