We give a survey of some recent results about the degeneration of families of polynomial automorphisms in three situations.A)In dimension 2 and length 2,whe
The group of automorphisms of the complex affine plane has a well known structure as an amalgamated free product of the triangular and affine subgroups.As s
For an affine variety X,an LND of k[X] corresponds to a oneparameter subgroup of automorphisms.We generate a subgroup SAut(X)of Aut(X)by all such automorphi
We study Mathieu subspaces of small codimension of the n-dimensional matrix algebra over the field K.Our main result is the classification of Mathieu subspa