Subir Sachdev
We argue that the resistivity of metals near strongly-coupled quantum critical points is not determined by the scattering rate of charged excitations near the Fermi surface. It is instead controlled by the dominant rate of momentum loss by any excitation, whether neutral or charged, or fermionic or bosonic. We compute the resistivity for critical theories in two dimensions, and find that it is dominated by the quantum fluctuations of bosonic collective excitations.