= Bondi shear
{c}
{title2=$C_{AB}$}
The <Bondi shear> is the leading trace-free angular distortion in an <asymptotically flat spacetime> described by <Bondi-Sachs coordinates>. In a common expansion, the angular <metric> is $h_{AB}=q_{AB}+C_{AB}/r+O(r^{-2})$, with $q^{AB}C_{AB}=0$.
Its retarded-time <derivative> determines the <Bondi news function>, with normalization depending on convention. The distinction matters: a nonzero but time-independent shear need not represent ongoing <radiation>, while changing shear describes radiative <degrees of freedom>. Changes between early and late configurations are also connected with <gravitational memory>.<Bondi-Sachs Formalism by Thomas Mädler and Jeffrey Winicour>[§3, asymptotic expansion and news]{ref}
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