There's a first time for everything...

[meanfreepath]

In computing a partition function for a stat mech homework problem (the partition function for a mean-field Hamiltonian of the XY model, which is basically a generalized Ising model where the spins are unit vectors that can point in any direction as opposed to just being up or down), an integral came up whose result is in terms of modified Bessel functions of the first kind.

Comments

[olifhar.livejournal.com]

I understood about half of this. I'll understand the other half in about a year, I suppose...