Abstract
The concept of the helicity modulus Yd(T), introduced by Fisher, Barber and Jasnow (see Phys. Rev., vol.A8, p.1111 (1973)), is applied to the ideal Bose gas in d dimensions. Above the critical temperature Tc,d, Y is found to vanish identically, while for Tc,d, Yd(T)=(h(cross)2 rho /m)(1-(T/Tc,d)12d/), where rho is the total density. The relevance of these results to more general theories of superfluidity is discussed.