A joint Workshop and Research in Groups between the France-Chile-Uruguay MathAmSud Project Geometry and Arithmetics of Algebraic Varieties of Non-Positive Curvature, the France-Chile ECOS-ANID Project ECOS n° C23E07 Equivariant Algebraic Geometry with a view towards Birational Geometry and Arithmetics and the France-Germany CNRS IEA Project Compact Torus Actions on Complex Algebraic Varieties.