Gross, BenedictMcMullen, Curtis2009-12-212002Gross, Benedict H., and Curtis T. McMullen. 2002. Automorphisms of even unimodular lattices and unramified Salem numbers. Journal of Algebra 257(2): 265-290. Revised 2008.0021-8693http://nrs.harvard.edu/urn-3:HUL.InstRepos:3446009In this paper we study the characteristic polynomials \(S(x)=\det(xI−F| II_{p,q})\) of automorphisms of even unimodular lattices with signature \((p,q)\). In particular, we show that any Salem polynomial of degree \(2n\) satisfying \(S(−1)S(1)=(−1)^n\) arises from an automorphism of an indefinite lattice, a result with applications to K3 surfaces.en-USJournal Article2009-12-2110.1016/S0021-8693(02)00552-5