Normal modes of inductively coupled LC circuits
= Normal modes of inductively coupled LC circuits
{title2=$\omega_\pm$}
Two identical circuits with self-<inductance> $L$, capacitance $C$ and <mutual inductance> $\mathcal M$ have same-sign and opposite-sign charge modes with $\omega_\pm^2=1/[C(L\pm\mathcal M)]$. The <inductance> matrix acts as the <mass matrix>; positivity requires $|\mathcal M|<L$.