Einstein 引力场方程
\begin{equation}\label{eq:Einstein-equation}
\begin{aligned}
R_{\mu \nu}-\frac{1}{2}Rg_{\mu \nu}+\Lambda g_{\mu \nu} = \kappa T_{\mu \nu}.
\end{aligned}
\end{equation}
引用式 \eqref{eq:Einstein-equation}。
Schrödinger 方程
\begin{equation}
\mathrm{i} \hbar \pdv{}{t} \ket{\psi} = H \ket{\psi}.
\end{equation}
Boltzmann 方程
$$
\pdv{f_{\alpha}}{t} + \bm{v} \dotproduct \grad_{\bm{x}} f_{\alpha} + \bm{a}_{\alpha} \dotproduct \grad_{\bm{v}} f_{\alpha} = C_{\alpha}\qty[f],
$$
其中 $\qty[f] = \qty(\qty{f_{\alpha}}) = \qty(f_{1}, \cdots, f_{n})$。
标量场之拉氏量
\begin{equation}
\begin{aligned}
\mathcal{L} = \frac{1}{2} \qty(\eta^{\mu \nu} \pdv{\phi}{x^{\mu}} \pdv{\phi}{x^{\nu}} – m^2 \phi^2).
\end{aligned}
\end{equation}
Lie 导数
\begin{equation}
\begin{aligned}
\mathscr{L}_{v} {T^{a_{1} \cdots a_{k}}}_{b_{1} \cdots b_{l}} =&{} v^{c} \nabla_{c} {T^{a_{1} \cdots a_{k}}}_{b_{1} \cdots b_{l}} \\
&{} – \sum_{i = 1}^{k} {T^{a_{1} \cdots c \cdots a_{k}}}_{b_{1} \cdots b_{l}} \nabla_{c} v^{a_{i}} \\
&{} + \sum_{j = 1}^{l} {T^{a_{1} \cdots a_{k}}}_{b_{1} \cdots c \cdots b_{l}} \nabla_{b_{j}} v^{c}.
\end{aligned}
\end{equation}

此为我之评论
先测试一下公式
评论区公式测试:
\begin{equation}
\begin{aligned}
R_{\mu \nu}.
\end{aligned}
\end{equation}
再测试一下代码
评论区代码测试:
测试结束。