# An equation with Feyman diagrams inside

I want to include this equation number 6.87 and 6.88 as same as in the screenshot to my project, please give some help to do this...

• Does this help? overleaf.com/learn/latex/feynman_diagrams Aug 4, 2020 at 17:10
• No, the things are so big, not able to use it inside equations @Alan Xiang Aug 4, 2020 at 17:33
• Can you please give an answer@Alan Xiang Aug 4, 2020 at 17:34
• Unfortunately, I do not know anything about Feyman diagrams, which means I am unable to recreate these symbols. However, if you are able to provide some sample code for Feyman diagrams, I think I do know how to adjust their size for equations. Aug 4, 2020 at 18:40
• You can use \resizebox to change the size of an object. Aug 4, 2020 at 18:43

Disclaimer: I'm an absolutely sporadic user of TikZ and I have no experience whatsoever in drawing Feynman diagrams with it (I still use feynmp for that...) but here's a shot at it

\documentclass{article}

\usepackage{tikz}

% \tikz picture vertically centered on math axis
\newcommand*{\ctikz}[2][]{\hbox{\mathsurround=3pt$\vcenter{\hbox{\tikz[#1]{#2}}}$}}
\usetikzlibrary{arrows.meta}
\newcommand*{\I}{\mathrm{i}}

\begin{document}

$Z[j] = \frac{\displaystyle \biggl[ 1 - \frac{\I\,g}{4!} \int \biggl( -3 \ctikz{ \draw(0,0)circle(0.2); \draw(0.4,0)circle(0.2); } + 6\I \ctikz{ \draw[{Rays[]}-{Rays[]}](0,0)--(0.8,0); \draw(0.4,0.2)circle(0.2);} + \ctikz{ \draw[{Rays[]}-{Rays[]}](0.3,0.3)--(-0.3,-0.3); \draw[{Rays[]}-{Rays[]}](-0.3,0.3)--(0.3,-0.3);} \biggr) \exp\biggl(-\frac{\I}{2} \int J \Delta_{\mathrm{F}} J \biggr)\biggr] \mathrm{d}z}% end of numerator {\displaystyle 1 - \frac{\I\,g}{4!} \int \Bigl(-3 \ctikz{\draw(0,0)circle(0.2);\draw(0.4,0)circle(0.2);}\Bigr) \mathrm{d}z}$

\end{document}


• Awesome, Thanks, Can I am unable to number this equation, can you tell me how to do it? @campa Aug 7, 2020 at 14:29
• @ROBINRAJ Use the equation environment. Or give a look at How can you number equations manually? Aug 7, 2020 at 14:34
• I tried using \label and \eqref, but not works in this case@campa Aug 7, 2020 at 14:55
• @ROBINRAJ Sorry but I can't read minds. If you have another problem then please ask a new question. Aug 7, 2020 at 14:59