# Package for calculating feynman digrams from number of external points, vectices and propagators

I usually manually compute most of the Feynman diagrams that I need for my assignment by hand. But lately, I've had to deal with $O(\lambda^2)$ with interactions involving both $\phi^3$ and $\phi^4$.

I boil down the problem to finding the possible number of Feynman diagrams visually given I know the No. of External Points, No. of $\phi^3 \equiv V_3$ and $\phi^4 \equiv V_4$ vertices's and No. of propagators.

For example, when

$E=2,P=4$ and $V_3=2,V_4=0$

$E=3$, $P=6$ and $V_3=3,V_4=0$.

So given this, I can immediately guess a diagrams of the following respectively as. How do I make the computer draw ALL such possible diagrams (if any) for an arbitrary $E,P,V_3,V_4$

• Okay, so maybe this is what you are looking for? Apr 5, 2016 at 10:18
• Hmm... i wasn't able to implement the concept of "topologies" in that package properly. Is there any simpler function to do so by which I jst have to input the above 3 quantities? It seems to me more like a graph theory problem. I'm not very comfortable with coding in general mathematica.
– user34128
Apr 5, 2016 at 10:27