Magnetic-Field and Pressure Dependence of Low-Temperature Resistivity in Uge2

We report measurements of resistivity rho in UGe2 at temperatures T down to 0.3 K, pressures P up to 19.8 kbar, and magnetic fields B-appl up to 17.5 T applied along the magnetic easy a axis. The coefficient A of the T-2 term of rho(T) is determined as a function of B-appl and P. In the large-moment ferromagnetic phase (the low-P/high-B-appl phase), A is found to be a function of the single parameter (B-appl-B-x) and approximately obeys a power law A proportional to(B-appl-B-x)(-1/2), where B-x is the transition field from the small- to the large-moment ferromagnetic phase. The T dependence of rho at fields just above B-x suggests a contribution to rho from excitations with a gapped spectrum.