Classification of horospherical invariant measures in higher rank: Teaser

This is an expository/teaser version of [arXiv:2601.22668] for a very special case of products of $\mathrm{C}\mathrm{A}\mathrm{T}(-1)$ spaces. We keep this on arXiv as many parts of the argument of [arXiv:2601.22668] are simplified in this special case.