3 papers
math.AG2026
The essential and Cremona dimensions of a group
Igor Dolgachev
The Cremona dimension of a group is the minimal such that is isomorphic to a subgroup of the Cremona group of birational transformations of an -dimensional rational…
math.HO2025
Igor Rostislavovich Shafarevich: in Memoriam
Igor Dolgachev
The prominent Russian mathematician Igor Rostislavovich Shafarevich passed away on February 19, 2017. In this article we supply his biography, discuss his many important contributi…
math.AG2024
Lagrangian tens of planes, Enriques surfaces and holomorphic symplectic fourfolds
Igor Dolgachev, Dimitri Markushevich
The Fano models of Enriques surfaces produce a family of tens of mutually intersecting planes in with a -dimensional moduli space. The latter is linked to several…