On the closure of the tame automorphism group of affine three-space
  We provide explicit families of tame automorphisms of the complex affine three-space which degenerate to wild automorphisms. This shows that the tame subgroup of the group of polynomial automorphisms of $\C^3$ is not closed, when the latter is seen as an infinite dimensional algebraic group.tomorphism group of affine three-space 
Eric Edo (ERIM), Pierre-Marie Poloni
math.AG