On Tuesday, February 3, 2015 at 8:18:58 PM UTC+1, Aaron Meurer wrote: > Do physics applications actually use summation notation with noninteger > limits? If so, what convention do they use? >
Summing over the states of fermions. But that's a convention. > @asmeurer. I only know they are used in summing the "half-integer" spins. > But i have no idea regarding the rules used. > Spins are usually half-integers in spacetime, but I know of some special cases, like propagation on waves on 2D surfaces, where one may build a theory with any rational spin quasi-particles, or something like that. Sometimes people with a background in mathematics get really scared when they see how mathematics is used in physics. The funniest I can think of is that multiple summations and integrals are often silently assumed to commute, even if they sum over to infinity. -- 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 sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/be18856c-e61c-4711-a5a4-b52194b306e6%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
