Characteristic polynomials of isometries of even unimodular lattices
Number Theory
2024-01-24 v1 Algebraic Geometry
Abstract
E. Bayer-Fluckiger gave a necessary and sufficient condition for a polynomial to be realized as the characteristic polynomial of a semisimple isometry of an even unimodular lattice, by describing the local-global obstruction, and the author extended the result. This article presents a systematic way to compute the obstruction. As an application, we give a necessary and sufficient condition for a Salem number of degree or to be realized as the dynamical degree of an automorphism of nonprojective K3 surface, in terms of its minimal polynomial.
Keywords
Cite
@article{arxiv.2401.12620,
title = {Characteristic polynomials of isometries of even unimodular lattices},
author = {Yuta Takada},
journal= {arXiv preprint arXiv:2401.12620},
year = {2024}
}