The result of angular frequency deduced from Eq 1.8 is quite confusing to me. Can some one walk me through it please?
cuz in his notation (eq1.8) he has rho bar he forgot the divsion symbol. this is a book called qft in stat phys by A. Abrikosov btw. previously he mentioned in low temp He4 energy is proportional to momentumWhy not ? It looks like the total energy of an HO... BTW I'm sorry but that's the only thing I could think of