44 citations · 52 across the 7 of their papers we have counts for
9 papers · 1 filter
On a result of Miyanishi-Masuda
Hubert Flenner, Mikhail Zaidenberg
Let be an affine surface admitting a unique affine ruling and a -action. Assume that the ruling has a unique degenerate fibre and that this fibre is irreducible. I…
On the uniqueness of -actions on affine surfaces
Hubert Flenner, Mikhail Zaidenberg
We prove that a normal affine surface over admits an effective action of a maximal torus () such that any other effective -act…
Locally nilpotent derivations on affine surfaces with a $\C^*$-action
Hubert Flenner, Mikhail Zaidenberg
We give a classification of normal affine surfaces admitting an algebraic group action with an open orbit. In particular an explicit algebraic description of the affine coordinate…
A Note on Generic Projections
Hubert Flenner, Mirella Manaresi
Let be a subvariety of dimension and a generic point. If the tangent variety Tan is equal to then for…
Normal affine surfaces with -actions
Hubert Flenner, Mikhail Zaidenberg
A classification of normal affine surfaces admitting a -action was given in the work of Białynicki-Birula, Fieseler and L. Kaup, Orlik and Wagreich, Rynes and others. We p…
Rational curves and rational singularities
Hubert Flenner, Mikhail Zaidenberg
We study rational curves on algebraic varieties, especially on normal affine varieties endowed with a $\C^*$-action. For varieties with an isolated singularity, we show that the pr…