Quotients of groups of birational transformations of cubic del Pezzo fibrations

Autor: Jérémy Blanc, Egor Yasinsky
Rok vydání: 2020
Předmět:
Zdroj: Journal de l’École polytechnique — Mathématiques. 7:1089-1112
ISSN: 2270-518X
DOI: 10.5802/jep.136
Popis: We prove that the group of birational transformations of a Del Pezzo fibration of degree 3 over a curve is not simple, by giving a surjective group homomorphism to a free product of infinitely many groups of order 2. As a consequence we also obtain that the Cremona group of rank 3 is not generated by birational maps preserving a rational fibration. Besides, its subgroup generated by all connected algebraic subgroups is a proper normal subgroup.
Comment: to appear in JEP
Databáze: OpenAIRE