Personne

Stefano Filipazzi

Boundedness of Elliptic Calabi-yau Threefolds

We show that elliptic Calabi-Yau threefolds form a bounded family. We also show that the same result holds for minimal terminal threefolds of Kodaira dimension 2, upon fixing the rate of growth of pluricanonical forms and the degree of a multisection of th ...

EUROPEAN MATHEMATICAL SOC-EMS2025

Complements and coregularity of Fano varieties

Stefano Filipazzi

We study the relation between the coregularity, the index of log Calabi-Yau pairs and the complements of Fano varieties. We show that the index of a log Calabi-Yau pair of coregularity is at most, where is the Weil index of. This extends a recent result du ...

2025

Rational points on 3-folds with nef anti-canonical class over finite fields

Stefano Filipazzi

We prove that a geometrically integral smooth projective 3-fold (Formula presented.) with nef anti-canonical class and negative Kodaira dimension over a finite field (Formula presented.) of characteristic (Formula presented.) and cardinality (Formula prese ...

2025

Index of coregularity zero log Calabi–Yau pairs

Stefano Filipazzi

We study the index of log Calabi–Yau pairs (X, B) of coregularity 0. We show that 2λ(KX + B) ∼ 0, where λ is the Weil index of (X, B). This is in contrast to the case of klt Calabi–Yau varieties, where the index can grow doubly exponentially with the dimen ...

2025

On the boundedness of n-folds with κ(X) = n - 1

Stefano Filipazzi

In this note, we study certain sufficient conditions for a set of minimal klt pairs ( X, triangle) with kappa ( X, triangle) = dim( X ) - 1 to be bounded. ...

European Mathematical Soc-Ems2024

Connectedness Principle for 3-Folds in Characteristic p > 5

Stefano Filipazzi

A conjecture, known as the Shokurov–Kollár connectedness principle, predicts the following. Let (X, B) be a pair, and let f : X → S be a contraction with −(KX + B) nef over S; then, for any point s ∈ S, the intersection f −1 (s) ∩ Nklt(X, B) has at most tw ...

2024

MODULI OF Q-GORENSTEIN PAIRS AND APPLICATIONS

Stefano Filipazzi

We develop a framework to construct moduli spaces of Q-Gorenstein pairs. To do so, we fix certain invariants; these choices are encoded in the notion of Q-stable pair. We show that these choices give a proper moduli space with projective coarse moduli spac ...

Univ Press Inc2024

Arithmetic and geometric deformations of threefolds

Stefano Filipazzi, Fabio Bernasconi

We show that mixed-characteristic and equicharacteristic small deformations of 3-dimensional canonical (resp., terminal) singularities with perfect residue field of characteristic p>5 are canonical (resp., terminal). We discuss applications to arithmetic a ...

Wiley2023

On the connectedness principle and dual complexes for generalized pairs

Stefano Filipazzi

Let (X,B) be a pair, and let f :X S be a contraction with -(K-x+B) nef over S. A conjecture, known as the Shokurov-Kollar connectedness principle, predicts thatf(-1) (s) boolean AND Nklt(X,B) has at most two connected components, where s is an element of ...

2023

The Jordan property for local fundamental groups

Stefano Filipazzi, Roberto Svaldi

We show the Jordan property for regional fundamental groups of klt singularities of fixed dimension. Furthermore, we prove the existence of effective simultaneous index 1 covers for n-dimensional klt singularities. We give an application to the study of lo ...

2022