Hi Stefan, This is cool. I would be interested in having this in sympy. Long time ago I wrote some diagram generating code for scalar diagrams:
https://github.com/certik/sympy/blob/wick/t.py but I didn't have time to polish it up and send a PR. As you correctly mentioned, there are lots of steps and actually several approaches to this problem and we should simply start adding such codes to sympy. What I wrote is just one little tiny bit, but it is still useful to check scalar particle diagrams. This is for relativistic theory. Then I have code here that generates the non-relativistic perturbation theory diagrams for total energy: https://github.com/certik/hfsolver/blob/master/src/diagrams_mbpt.py here is the corresponding Fortran code for evaluating them: https://github.com/certik/hfsolver/blob/master/src/mbpt.f90 these 3 files are generated: https://github.com/certik/hfsolver/blob/master/src/mbpt2.f90 https://github.com/certik/hfsolver/blob/master/src/mbpt3.f90 https://github.com/certik/hfsolver/blob/master/src/mbpt4.f90 and then the same for Green's functions: https://github.com/certik/hfsolver/blob/master/src/diagrams_gf.py and the Fortran code (this one I wrote by hand): https://github.com/certik/hfsolver/blob/master/src/gf2.f90 Anyway, we should have this in sympy. Ondrej -- You received this message because you are subscribed to the Google Groups "sympy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sympy. For more options, visit https://groups.google.com/groups/opt_out.
