The tame and the wild automorphisms of an affine quadric threefold
  We prove the existence of wild automorphisms on an affine quadric threefold. The method we use is an adaptation of the one used by Shestakov and Umirbaev to prove the existence of wild automorphisms on the affine three dimensional space. 
St\'ephane Lamy, St\'ephane V\'en\'ereau
math.AG