Equations
\begin{equation}
\sigma_{abs} = \frac{e^2 \lambda^2}{4 \epsilon_0 m_e c_0^2 n} g(\lambda) f_{osc}^{s_0 \to s_1}
\end{equation}
\begin{equation}
\sigma_{abs} = \frac{e^2 \lambda^2}{4 \epsilon_0 m_e c_0^2 n} g(\lambda) f_{osc}^{s_0 \to s_1}
\end{equation}