Nuisance tangent space
= Nuisance tangent space
{title2=$\mathcal N$}
The nuisance tangent space is the closed linear span of <score functions> from <statistical paths> that vary the <nuisance parameter> while fixing the target <statistical parameter>. It is a <closed subspace of a Hilbert space> inside $L^2_0(P)$. Removing its component from a parametric <score function> leaves the information that nuisance variation cannot imitate.