On bundles of matrix pencils under strict equivalence

Bundles of matrix pencils (under strict equivalence) are sets having the same Kronecker canonical form, up to eigenvalues (namely, they an infinite union orbits under equivalence). The notion bundle for was introduced in 1990's, following matrices similarity, by Arnold 1971, and it has been extensively used since then. Despite amount literature devoted describing topology bundles pencils, some relevant questions remain still open this context. For example, two: (a) provide a characterization inclusion relation between closures (in standard topology) bundles; (b) their closure? main goal paper is providing explicit answer these two questions. In order get answer, we also review and/or formalize notions results already existing literature. We prove that as well polynomials (defined set m × n grade spectral information, eigenvalues) closure.