Does anyone know if sigma and pi bonds in chemistry have any mathematical definition? The reason I'm asking this is because I've recently read a lot about cycles and permutations, and they seem to primarily use sigma and pi in their notation when multiplying 2 separate cycles. Just a heads up, it might not even be related and was just curious.
What I knew is that the $\sigma$-bond involves either $sp$, $sp^2$ or $sp^3$ hybridization whereas $\pi$-bond involves overlapping of $p$-orbitals. May refer to LCAO.