5 apr 2017 -- 15:00
Aula di Consiglio, Dip.Matematica, Università "La Sapienza", Roma
Abstract.
A line arrangement of 3n lines in CP2 satisfies Hirzebruch property if each line intersect others in (n+1) points. Hirzebruch asked if all such arrangements are related to finite complex reflection groups. We give a positive answer to this question in the case when the line arrangement in CP2 is real, confirming that there exist exactly four such arrangements.