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Federico Fallucca

Publications and source records attributed to Federico Fallucca.

9 recordsLinked to original sources
arXiv2026

The Picard number of fibred Mori dream surfaces

Let $S$ be a smooth complex projective surface endowed with a fibration $f \colon S \to C$ onto a smooth projective curve $C$. We prove that, if $S$ is a Mori dream space (or, more generally, if its pseudo-effective cone is polyhedral) then the Picard number $\rho(S)$ can be effectively computed by counting the irreducible components of the reducible fibres of $f$. A first simple consequence is that, given an elliptic fibration $f \colon S \to \mathbb{P}^1$ with a section and such that $S$ is a Mori dream space, the Mordell-Weil group of the general fibre of $f$ is finite. The main application is a simple criterion for proving that a surface fibred over a curve is not a Mori dream space. We show that certain Horikawa surfaces, Fermat surfaces in $\mathbb{P}^{3}$ of every degree $\ge 4$, particular product-quotient surfaces, and the minimal simply connected numerical Godeaux surface constructed by Craighero and Gattazzo are not Mori dream spaces.

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arXiv2026

Some rational subvarieties of moduli spaces of stable vector bundles

Let X be a smooth complex irreducible projective variety of dimension $n \geq 2$ and $H$ be an ample line bundle on $X$. In this paper, we construct families of $\mu_H$-stable vector bundles on $X$ having fixed determinant and rank $r$, which are generated by $r+1$ global sections, parametrized by Grassmanian varieties. This gives into the corresponding moduli spaces special subvarieties birational to Grassmannian.

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arXiv2025

On Rigid Varieties Isogenous to a Product of Curves

In this note, we study rigid complex manifolds that are realized as quotients of a product of curves by a free action of a finite group. They serve as higher-dimensional analogues of Beauville surfaces. Using uniformization, we outline the theory to characterize these manifolds through specific combinatorial data associated with the group under the assumption that the action is diagonal and the manifold is of general type. This leads to the notion of a $n$-fold Beauville structure. We define an action on the set of all $n$-fold Beauville structures of a given finite group that allows us to distinguish the biholomorphism classes of the underlying rigid manifolds. As an application, we give a classification of these manifolds with group $\mathbb Z_5^2$ in the three dimensional case and prove that this is the smallest possible group that allows a rigid, free and diagonal action on a product of three curves. In addition, we provide the classification of rigid 3-folds $X$ given by a group acting faithfully on each factor for any value of the holomorphic Euler number $\chi(\mathcal O_X) \geq -5$.

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arXiv2024

On the classification of product-quotient surfaces with $q=0$, $p_g=3$ and their canonical map

In this work we present new results to produce an algorithm that returns, for any fixed pair of natural integers $K^2$ and $\chi$, all regular surfaces $S$ of general type with self-intersection $K_S^2=K^2$ and Euler characteristic $\chi(\mathcal O_S)=\chi$, that are product-quotient surfaces. The key result we obtain is an algebraic characterization of all families of regular product-quotients surfaces, up to isomorphism, arising from a pair of $G$-coverings of $\mathbb P^1$. As a consequence of our work, we provide a classification of all regular product-quotient surfaces of general type with $23\leq K^2\leq 32$ and $\chi(\mathcal O_S)=4$. Furthermore, we study their canonical map and present several new examples of surfaces of general type with a high degree of the canonical map.

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arXiv2023

Smooth k-double covers of the plane of geometric genus 3

In this work we classify all smooth surfaces with geometric genus equal to three and an action of a group G isomorphic to (Z/2)^k such that the quotient is a plane. We find 11 families. We compute the canonical map of all of them, finding in particular a family of surfaces with canonical map of degree 16 that we could not find in the literature. We discuss the quotients by all subgroups of G finding several K3 surfaces with symplectic involutions. In particular we show that six families are families of triple K3 burgers in the sense of Laterveer.

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arXiv2022

Examples of surfaces with canonical maps of degree $12$, $13$, $15$, $16$ and $18$

In this note we present examples of complex algebraic surfaces with canonical maps of degree $12$, $13$, $15$, $16$ and $18$. They are constructed as quotients of a product of two curves of genus $10$ and $19$ using certain non-free actions of the group $S_3\times \mathbb Z_3^2$. To our knowledge there are no other examples in literature of surfaces with canonical map of degree $13$, $15$ and $18$.

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arXiv2022

Some surfaces with canonical maps of degree $10$, $11$ and $14$

In this note we present examples of complex algebraic surfaces of general type with canonical maps of degree $10$, $11$ and $14$. They are constructed as quotients of a product of two Fermat septics using certain free actions of the group $\mathbb Z_7^2$.

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arXiv2021

Some surfaces with canonical map of degree 4

In this short note we construct unbounded families of minimal surfaces of general type with canonical map of degree 4 such that the limits of the slopes assume countably many different values among 6+2/3 and 8.

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