5 papers
Harmonic morphisms and dynamical invariants in network renormalization
Francesco Maria Guadagnuolo, Marco Nurisso, Federica Galluzzi +2
Renormalization of complex networks requires principled criteria for assessing whether a coarse-graining preserves dynamical content. We prove that discrete harmonic morphisms -- s…
Ulrich and Instanton Bundles on Special Cubic Fourfolds
Gianfranco Casnati, Daniele Faenzi, Federica Galluzzi
We study instanton and Ulrich bundles on hypersurfaces of the projective space, with a focus on special cubic fourfolds and generalized Pfaffians, notably defined by skew-symmetric…
The two extremal rays of some Hyper-Kähler fourfolds
Federica Galluzzi, Bert Van Geemen
We consider projective Hyper-Kähler manifolds of dimension four that are deformation equivalent to Hilbert squares of K3 surfaces. In case such a manifold admits a divisorial contr…
Some remarks on Brauer Classes of K3-type
Federica Galluzzi, Bert van Geemen
An element in the Brauer group of a general complex projective surface defines a sublattice of the transcendental lattice of . We consider those elements of prime order…
Invariants of Vanishing Brauer Classes
Federica Galluzzi, Bert van Geemen
A specialization of a K3 surface with Picard rank one to a K3 with rank two defines a vanishing class of order two in the Brauer group of the general K3 surface. We give the B-fiel…