After presenting the main notions and results about congruences of k-planes, we dwell upon congruences of lines, mainly of order one. We survey the classification results in the projective spaces of dimension 3 and 4, which are almost complete, and the (partial) results and some conjectures in higher dimension. Finally we present some new results, in particular a degree bound for varieties with one apparent double point, a new class of examples with focal locus of high degree, and some general results about the classification of first order congruences of lines in P^4 with reducible focal surface.

On congruences of linear spaces of order one

DE POI, Pietro;
2007

Abstract

After presenting the main notions and results about congruences of k-planes, we dwell upon congruences of lines, mainly of order one. We survey the classification results in the projective spaces of dimension 3 and 4, which are almost complete, and the (partial) results and some conjectures in higher dimension. Finally we present some new results, in particular a degree bound for varieties with one apparent double point, a new class of examples with focal locus of high degree, and some general results about the classification of first order congruences of lines in P^4 with reducible focal surface.
File in questo prodotto:
File Dimensione Formato  
rossi.pdf

non disponibili

Tipologia: Altro materiale allegato
Licenza: Non pubblico
Dimensione 249.2 kB
Formato Adobe PDF
249.2 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11390/690740
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 4
  • ???jsp.display-item.citation.isi??? ND
social impact