Singular tuples of matrices is not a null cone (and, the symmetries of algebraic varieties).

Visu Makam Avi Wigderson Singular tuples of matrices is not a null cone (and, the symmetries of algebraic varieties). TR19-114 2019 TR19 Electron. Colloquium Comput. Complex. https://eccc.weizmann.ac.il/report/2019/114 db/journals/eccc/eccc26.html#MakamW19