@article{Liu2022, 
author = {Yingqi Liu},
title = {Additive actions on hyperquadrics of corank two},
year = {2022},
journal = {Electronic Research Archive},
volume = {30},
number = {1},
pages = {1-34},
keywords = {commutative unipotent group action, equivariant compactification, hyperquadric of corank two, symmetric bilinear form, simultaneous orthogonal similarity},
url = {https://www.sciopen.com/article/10.3934/era.2022001},
doi = {10.3934/era.2022001},
abstract = {For a projective variety  X in  Pm of dimension  n, an additive action on  X is an effective action of  Gan on  Pm such that  X is  Gan-invariant and the induced action on  X has an open orbit. Arzhantsev and Popovskiy have classified additive actions on hyperquadrics of corank 0 or 1. In this paper, we give the classification of additive actions on hyperquadrics of corank 2 whose singularities are not fixed by the  Gan-action.}
}