Flexible affine cones and flexible coverings
  We provide a new criterion for flexibility of cones over varieties covered by flexible affine varieties. We apply this criterion to prove flexibility of affine cones over secant varieties of Segre--Veronese embeddings and over certain Fano threefolds. We further prove flexibility of total coordinate spaces of Cox rings of del Pezzo surfaces. 
Matheusz Micha{\l}ek, Alexander Perepechko, Hendrik S\"u{\ss}
math.AG