LAUSR

We show that the resistivity in each phase of the high-Tc cuprates is a special case of a general expression derived from the Kubo formula. We obtain, in particular, the T-linear behavior in the strange metal and upper pseudogap phases, the pure T 2 Fermi liquid behavior observed in the strongly overdoped regime as well as in the mid-pseudogap phase. We also describe the T1+δ behavior that interpolates the linear and quadratic behaviors in the crossover regime. We calculate the coefficients: (a) of T in the linear regime and show that it is proportional to the pseudogap transition temperature T *(x); (b) of the T  2-term in the Fermi Liquid regime, without adjusting any parameter; and (c) of the T 1.6 term in the crossover regime, all in excellent agreement with the experimental data. From our model, we are able to infer that the resistivity in cuprates is caused by the scattering of holes by excitons, which naturally form as holes are doped into the electron background.