Midpoints for Thompson's metric on symmetric cones
arXiv:1507.03087
Abstract
We characterise the affine span of the midpoints sets for Thompson's metric on symmetric cones in terms of a translation of the zero-component of the Peirce decomposition of an idempotent. As a consequence we derive an explicit formula for the dimension of the affine span of the midpoints sets in case the associated Euclidean Jordan algebra is simple.
11 pages