= Anisotropic vector for a form
= Anisotropic vectors for a form
{synonym}
A vector is anisotropic for a <quadratic form> if $Q(v)\ne0$, and for a <Hermitian form> if $h(v,v)\ne0$. The complementary zero-value condition is isotropy. For a <symmetric bilinear form> in odd <characteristic of a field>, this agrees with the associated <quadratic form>. A <nondegenerate> <alternating bilinear form> has all self-pairings zero, so nondegeneracy must not be confused with the existence of anisotropic vectors.
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