English

Reductions between short vector problems and simultaneous approximation

Number Theory 2021-04-08 v3

Abstract

In 1982, Lagarias showed that solving the approximate Shortest Vector Problem also solves the problem of finding good simultaneous Diophantine approximations. Here we provide a deterministic, dimension-preserving reduction in the reverse direction. It has polynomial time and space complexity, and it is gap-preserving under the appropriate norms. We also give an alternative to the Lagarias algorithm by first reducing his version of simultaneous approximation to one with no explicit range in which a solution is sought.

Keywords

Cite

@article{arxiv.2003.12173,
  title  = {Reductions between short vector problems and simultaneous approximation},
  author = {Daniel E. Martin},
  journal= {arXiv preprint arXiv:2003.12173},
  year   = {2021}
}

Comments

16 pages, 3 algorithms. Version 2 corrects a mistake in Proposition 2.1 that made it only correct under the sup norm, as well as an erroneous determinant computation that immediately followed Algorithm 3. Version 3 makes minor changes to match the published paper

R2 v1 2026-06-23T14:28:44.353Z