M T W T F S S
 
 
 
 
 
 
1
 
2
 
3
 
4
 
5
 
6
 
7
 
8
 
9
 
10
 
11
 
12
 
13
 
14
 
15
 
16
 
17
 
18
 
19
 
20
 
21
 
22
 
23
 
24
 
25
 
26
 
27
 
28
 
29
 
30
 
31
 
 
 
 
 
 
Add to My Calendar

Responsabili:

Federica Galluzzi  ed  Elena Martinengo
 

Nel calendario si indicano i seminari di geometria algebrica e altre attività di interesse, organizzate dall'Università e dal Politecnico di Torino.

Correspondences acting on constant cycle curves on K3 surfaces

Printer-friendly versionSend by emailPDF version

Data: 

22/10/2024 - 16:00

Aula: 

Aula C

Speaker: 

Sara Torelli

Categoria: 

Seminari di Algebra e Geometria Algebrica

Afferenza: 

Università di Roma Tre

Descrizione: 

Abstract: Constant cycle curves on a K3 surface $X$ defined over $\mathbb{C}$ are curves whose points all define the Beauville-Voisin class in the Chow group of $X$. They were first considered by Huybrechts and Voisin as a generalization of the notion of rational curve. In this talk, we introduce correspondences $Z \subseteq X\times X$ acting on constant cycle curves, and we study geometric examples that can potentially improve our current understanding of constant cycle curves. More precisely, for a general primitively polarised K3 surface $(X, H)$ of genus $p\geq 2$, we consider for any $k\geq 2$ and any $0\leq \delta\leq p$ the locus $Z_{k,\delta}(X,H)\subseteq X\times X$ of pairs of points $(p,q)$ contained in some $\delta$-nodal curve $C$ with the property that $p-q$ is $k$-torsion in the Jacobian of the normalization of $C$. We prove that this locus is nonempty of the expected dimension $2$ if and only if a certain Brill-Noether number is non negative, and that, when nonempty, it gives the desired examples. This is part of a work in progress with Andreas Leopold Knutsen.