![知道如何绘制这个费曼图吗?](https://linux22.com/image/428241/%E7%9F%A5%E9%81%93%E5%A6%82%E4%BD%95%E7%BB%98%E5%88%B6%E8%BF%99%E4%B8%AA%E8%B4%B9%E6%9B%BC%E5%9B%BE%E5%90%97%EF%BC%9F.png)
答案1
不确定这是否是费曼积分。
\documentclass[tikz,border=3mm]{standalone}
\begin{document}
\begin{tikzpicture}[declare function={a=1.2;b=1.5;}]
\draw[teal,dashed,rotate=-22.5] (90:a) foreach \X in {45,0,...,-180}
{-- (\X:a) edge ++ (\X:0.5)} -- (135:a);
\draw node[circle,fill,draw,inner sep=0.8ex](O){}
foreach \X [count=\Y] in {45,0,...,-225}
{(\X:b) node[circle,draw,thin,inner sep=0.5ex](p\Y){} edge[very thick] (O)};
\path foreach \X [count=\Y from 2] in {n-1,n,1,2,3}
{(p\Y) to[edge label={$a_{\X}$}] (O)};
\end{tikzpicture}
\end{document}