Abstract
Let K be a bounded convex domain in R-2 symmetric about the origin. The critical locus of K is defined to be the (non-empty compact) set of lattices Lambda in R-2 of smallest possible covolume such that Lambda boolean AND K = {0}. These are classical objects in geometry of numbers; yet all previously known examples of critical loci were either finite sets or finite unions of closed curves. In this paper we give a new construction which, in particular, furnishes examples of domains having critical locus of arbitrary Hausdorff dimension between 0 and 1. (C) 2021 Royal Dutch Mathematical Society (KWG). Published by Elsevier B.V. All rights reserved.