Lucas, Andrew JamesDavison, RichardSachdev, Subir2016-09-092016Lucas, Andrew, Richard A. Davison, and Subir Sachdev. 2016. “Hydrodynamic Theory of Thermoelectric Transport and Negative Magnetoresistance in Weyl Semimetals.” Proc Natl Acad Sci USA 113 (34) (August 10): 9463–9468. doi:10.1073/pnas.1608881113.0027-8424http://nrs.harvard.edu/urn-3:HUL.InstRepos:28318149We present a theory of thermoelectric transport in weakly disordered Weyl semimetals where the electron-electron scattering time is faster than the electron-impurity scattering time. Our hydrodynamic theory consists of relativistic fluids at each Weyl node, coupled together by perturbatively small inter-valley scattering, and long-range Coulomb interactions. The conductivity matrix of our theory is Onsager reciprocal and positive-semidefinite. In addition to the usual axial anomaly, we account for the effects of a distinct, axial-gravitational anomaly expected to be present in Weyl semimetals. Negative thermal magnetoresistance is a sharp, experimentally accessible signature of this axial-gravitational anomaly, even beyond the hydrodynamic limit.en-USJournal Article2016-09-0910.1073/pnas.1608881113