Cremona Orbits in ${\mathbb{P}}^4$ and Applications

Abstract

This article is motivated by the authors interest in the geometry of the Mori dream space ${\mathbb{P}}^4$ blown up in $8$ general points. In this article we develop the necessary technique for determining Weyl orbits of linear cycles for the four-dimensional case, by explicit computations in the Chow ring of the resolution of the standard Cremona transformation. In particular, we close this paper with applications to the question of the dimension of the space global sections of effective divisors having at most $8$ base points.