Garibaldi, Skip
[Emory University]
Parimala, Raman
[Emory University]
Tignol, Jean-Pierre
[UCL]
We define an invariant of torsors under adjoint linear algebraic groups of type C_n-equivalently, central simple algebras of degree 2n with symplectic involution-for n divisible by 4 that takes values in H^3(F, mu_2). The invariant is distinct from the few known examples of cohomological invariants of torsors under adjoint groups. We also prove that the invariant detects whether a central simple algebra of degree 8 with symplectic involution can be decomposed as a tensor product of quaternion algebras with involution.
Bibliographic reference |
Garibaldi, Skip ; Parimala, Raman ; Tignol, Jean-Pierre. Discriminant of Symplectic Involutions. In: Pure and Applied Mathematics Quarterly, Vol. 5, no. 1, p. 349-374 (2009) |
Permanent URL |
http://hdl.handle.net/2078.1/35861 |