Ulrich Betke

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Hadwiger showed by computing the intrinsic volumes of a regular simplex that a rectangular simplex is a counterexample to Wills’s conjecture for the relation between the lattice point enumerator and the intrinsic volumes in dimensions not less than 441. Here we give formulae for the volumes of spherical polytopes related to the intrinsic volumes of the(More)
It is a well known fact that for every polynomial time algorithm which gives an upper bound V (K) and a lower bound V (K) for the volume of a convex set K ⊂ E, the ratio V (K)/V (K) is at least (cd/ log d). Here we describe an algorithm which gives for ǫ > 0 in polynomial time an upper and lower bound with the property V (K)/V (K) ≤ d!(1 + ǫ).
We study the following generalization of the inradius: For a convex body K in the d-dimensional Euclidean space and a linear k-plane L we define the inradius of K with respect to L by rL(K) = max{r(K;x + L) : x ∈ E}, where r(K;x + L) denotes the ordinary inradius of K ∩ (x+L) with respect to the affine plane x+L. We show how to determine rL(P ) for(More)