Searcharxiv⌕ Search

arXiv subjects

Manuel González Villa

Publications and source records attributed to Manuel González Villa.

9 recordsLinked to original sources

Denef-Loeser zeta functions of suspensions and Lê-Yomdin singularities

The holomorphy conjecture for suspensions of plane curve singularities and the holomorphy and monodromy conjectures for Lê-Yomdin singularities of surfaces are proved. The first part of this paper provides formulæ for the motivic and topological zeta functions for a family of hypersurfaces, including the suspensions by an arbitrary number of points and which are more general than Thom-Sebastiani type. These formulae generalize and are inspired by the description of the topological and the 2-twisted topological zeta functions of suspensions by 2 points of hypersurfaces, due to the first named author, Cassou-Noguès, Luengo and Melle. The new general formulæ deal with arbitrary values of the twisting parameter. An interesting feature of these general formulæ is the appearance of values of the Jordan's totient function as coefficients of the topological and the twisted topological zeta functions of some auxiliary hypersurfaces of smaller dimension.

math.AG↗

Bernstein-Sato polynomial and related invariants for meromorphic functions

We develop a theory of Bernstein-Sato polynomials for meromorphic functions and we use it to study the analytic continuation of Archimedian local zeta functions in this setting. We also introduce both an analytic and an algebraic theory of multiplier ideals for meromorphic functions and relate the jumping numbers of these multiplier ideals to the roots of the Bernstein-Sato polynomials.

math.CV↗

Multiplier ideals of plane curve singularities via Newton polygons

We give an effective method to determine the multiplier ideals and jumping numbers associated with a curve singularity $C$ in a smooth surface. We characterize the multiplier ideals in terms of certain Newton polygons, generalizing a theorem of Howald, which holds when $C$ is Newton non-degenerate with respect to some local coordinate system. The method uses toroidal embedded resolutions and generating sequences of families of valuations, and can be extended to some classes of higher dimensional hypersurface singularities.

math.AG↗

On a quadratic form associated with a surface automorphism and its applications to Singularity Theory

We study the nilpotent part $N'$ of a pseudo-periodic automorphism $h$ of a real oriented surface with boundary $Σ$. We associate a quadratic form $Q$ defined on the first homology group (relative to the boundary) of the surface $Σ$. Using the twist formula and techniques from mapping class group theory, we prove that the form $\tilde{Q}$ obtained after killing ${\ker N}$ is positive definite if all the screw numbers associated with certain orbits of annuli are positive. We also prove that the restriction of $\tilde Q$ to the absolute homology group of $Σ$ is even whenever the quotient of the Nielsen-Thurston graph under the action of the automorphism is a tree. The case of monodromy automorphisms of Milnor fibers $Σ=F$ of germs of curves on normal surface singularities is discussed in detail, and the aforementioned results are specialized to such situation. Moreover, the form $\tilde{Q}$ is computable in terms of the dual resolution or semistable reduction graph, as illustrated with several examples. Numerical invariants associated with $\tilde{Q}$ are able to distinguish plane curve singularities with different topological types but same spectral pairs. Finally, we discuss a generic linear germ defined on a superisolated surface. In this case the plumbing graph is not a tree and the restriction of $\tilde Q$ to the absolute monodromy of $Σ=F$ is not even.

math.AG↗

$F$-thresholds and test ideals of Thom-Sebastiani type polynomials

We provide a formula for $F$-thresholds of a Thom-Sebastiani type polynomial over a perfect field of prime characteristic. This result extends the formula for the $F$-pure threshold of a diagonal hypersurface. We also compute the first test ideal of Thom-Sebastiani type polynomials. Finally, we apply our result to find hypersurfaces where the log canonical thresholds equals the $F$-pure thresholds for infinitely many prime numbers.

math.AC↗

The monodromy conjecture for plane meromorphic germs

A notion of Milnor fibration for meromorphic functions and the corresponding concepts of monodromy and monodromy zeta function have been introduced in [GZLM1]. In this article we define the topological zeta function for meromorphic germs and we study its poles in the plane case. We show that the poles do not behave as in the holomorphic case but still do satisfy a generalization of the monodromy conjecture.

math.AG↗

Motivic Milnor fiber of a quasi-ordinary hypersurface

Let $f$ be a germ of complex analytic function at $({\mathbf{C}}^{d+1}, 0)$ such that its zero level defines an irreducible germ of quasi-ordinary hypersurface $(S,0)$. We describe the motivic Igusa zeta function, the motivic Milnor fibre and the Hodge-Steenbrink spectrum of $f$ at 0 in terms of topological invariants of the quasi-ordinary hypersurface $(S,0)$.

math.AG↗