English

Asymptotic hollowness of lattice simplices

Number Theory 2021-08-17 v2

Abstract

An (n1)(n-1)-tuple a=(a(1),,a(n1))a = (a(1), \dots, a(n-1)) consisting of positive integers is said to be asymptotically hollow if there exist infinitely many positive integers NN such that the convex hull, K(a(n))K(a(n)), in nn-dimensional Euclidean space of {0,e1,,en1,α(N)T}\{ 0,e_1, \dots, e_{n-1}, \alpha(N)^T\} is hollow (has no lattice points in its interior), where eie_i run over all but the last standard basis elements, and α(N)\alpha(N) is the row (a(1),,a(N1),N)(a(1), \dots, a(N-1), N). The tuple is trivial if mina(i)=1\min a(i) = 1. Nontrivial asymptotically hollow tuples are characterized in terms of modular inequalities, and turn out to be rare. We show that for a tuple aa, there exists an effectively computable constant CC (depending on aa) such that if for some N>CN > C, K(α(N))K(\alpha(N)) is (not) hollow, then for all M>CM > C, K(α(M))K(\alpha(M)) is (not) hollow (respectively). When n=4n = 4, the nontrivial asymptotically hollow triples are completely determined; there are eleven of them, together with a one-parameter family.

Keywords

Cite

@article{arxiv.2012.06004,
  title  = {Asymptotic hollowness of lattice simplices},
  author = {David Handelman},
  journal= {arXiv preprint arXiv:2012.06004},
  year   = {2021}
}

Comments

25 pages; intro changed, and typos fixed