English

Volume bounds for shadow covering

Metric Geometry 2014-01-07 v1

Abstract

For n >= 2 a construction is given for a large family of compact convex sets K and L in n-dimensional Euclidean space such that the orthogonal projection L_u onto the subspace u^\perp contains a translate of the corresponding projection K_u for every direction u, while the volumes of K and L satisfy V_n(K) > V_n(L). It is subsequently shown that, if the orthogonal projection L_u onto the subspace u^\perp contains a translate of K_u for every direction u, then the set (n/(n-1))L contains a translate of K. If follows that V_n(K) <= (n/(n-1))^n V_n(L). In particular, we derive a universal constant bound V_n(K) <= 2.942 V_n(L), independent of the dimension n of the ambient space. Related results are obtained for projections onto subspaces of some fixed intermediate co-dimension. Open questions and conjectures are also posed.

Keywords

Cite

@article{arxiv.1109.1619,
  title  = {Volume bounds for shadow covering},
  author = {Christina Chen and Tanya Khovanova and Daniel A. Klain},
  journal= {arXiv preprint arXiv:1109.1619},
  year   = {2014}
}

Comments

19 pages, 3 figures

R2 v1 2026-06-21T19:01:31.850Z