I'm working through Schakel's 'Boulevard of broken symmetries' and I don't get an equation connect to the Coulomb gas problem. The equation in question is (5.77) on page 161. Luckily, you may look it up in http://books.google.com/books?id=OA...EwAQ#v=onepage&q=sine gordon coulomb&f=false". I guess I'm missing something obvious but it seems like (5.77) is wrong; e.g. if one calculates both sides for N=2. Any ideas?