Аннотация:
A classical result due to Seidenberg states that every singular
holomorphic foliation on a complex surface can be turned
into a foliation possessing only elementary singular points by
means of a finite sequence of (one-point) blow-ups. Here we
remind the reader that a singular point $p$ is said to be elementary
if the foliation $\mathcal F$ in question has at least one eigenvalue
different from zero at $p$. However, in dimension 3, the natural
analogue of Seidenberg theorem no longer holds as shown by
Sanz and Sancho.
More recently, two major works have been devoted to this
problem. In [1], Cano, Roche and Spivakovsky have worked
out a reduction procedure using (standard) blow-ups. The
main disadvantage of their theorem lies, however, in the fact
that some of their final models are quadratic and hence have
all eigenvalues equal to zero. On the other hand, McQuillan
and Panazzolo [2] have successfully used weighted blow-ups to
obtain a satisfactory desingularization theorem in the category
of stacks, rather than in usual complex manifolds.
A basic question is how far these theorems can be improved
if we start with a complete vector field on a complex manifold
of dimension 3, rather than with a general 1-dimensional holomorphic
foliation. In this context of complete vector fields, we
will prove a sharp desingularization theorem. Our proof of the
mentioned result will naturally require us to revisit the works
of Cano-Roche-Spivakovsky and of McQuillan-Panazzolo on
general 1-dimensional foliations. In particular, by building
on [1], our discussion will also shed some new light on the
desingularization problem for general 1-dimensional foliation
on complex manifolds of dimension 3.
Язык доклада: английский
Список литературы
F. Cano, C. Roche & M. Spivakovsky, “Reduction of singularities of three-dimensional line foliations”, Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Math. RACSAM, 108:1 (2014), 221–258
M. McQuillan & D. Panazzolo, “Almost étale resolution of foliations”, J. Differential Geometry, 95 (2013), 279–319
J. Rebelo & H. Reis, On resolution of 1-dimensional foliations on 3-manifolds, arXiv: 1712.10286