Isotropy of orthogonal involutions

Nikita A. Karpenko, Jean-Pierre Tignol
2013 American Journal of Mathematics  
An orthogonal involution on a central simple algebra becoming isotropic over any splitting field of the algebra, becomes isotropic over a finite odd degree extension of the base field (provided that the characteristic of the base field is not 2).
doi:10.1353/ajm.2013.0011 fatcat:36bfw7tyfjanrpjdgqahtabwwu