arXiv subjects

Marcelo Veloso

Publications and source records attributed to Marcelo Veloso.

4 recordsLinked to original sources

arXiv2026

On the Tame Isotropy Group of Locally Finite Derivations of K[X,Y]

Let K be an algebraically closed field of characteristic zero. We study the tame isotropy group Tame_D(K[X,Y]) of locally finite derivations of the polynomial ring K[X,Y], using Van den Essen's classification up to conjugation. For each normal form, we explicitly determine the corresponding tame isotropy group. We then compare Tame_D(K[X,Y]) with the tame isotropy group of the associated exponential automorphism exp(D), and prove that these groups always coincide. This stands in contrast to the behaviour of the full automorphism group, where such an equality may fail for derivations with a nontrivial semisimple part.

math.AG↗

arXiv2026

On isotropy group of locally finite derivations on $\mathbb{K}[X,Y]$

In this paper, we study the isotropy groups of locally finite derivations of the polynomial ring $\mathbb{K}[X,Y]$, using Van den Essen's classification of locally finite derivations in two variables. We compare the isotropy group of a locally finite derivation with that of its associated exponential automorphism, showing that they coincide in the locally nilpotent case, whereas they may differ when the semisimple part is nontrivial. We also prove that every nonzero locally finite derivation has a nontrivial isotropy group.

math.AC↗

arXiv2025

On the tame isotropy group of a derivation

We introduce the tame isotropy group of a derivation of a polynomial ring. We study this group for certain triangular derivations up to three variables, for simple derivations in two variables, and for simple Shamsuddin derivations in any polynomial ring.

math.AC↗

arXiv2020

On Isotropy Group of Danielewski Surfaces

In the present work we consider differential rings of the form $(\mathcal B,D)$ where $\mathcal B$ is a Danielewski surface and $D$ is a locally nilpotent derivation on $\mathcal B$. Influenced by several recent works, we describe the isotropy group of a locally nilpotent derivation, $D$, on Danielewski surfaces, in the cases $xy = φ(z)$, $x^ny=φ(Z)$, and $f(x)x = φ(z)$.

math.AG↗