Transverse thermoelectric response as a probe for existence of quasiparticles

The electrical Hall conductivities of any anisostropic interacting system with reflection symmetry obey sigma xy sigma yx In contrast I will show that the analogous relation between the transverse Peltier coefficients alpha xy alpha yx does not generally hold in the same system unless a quasiparticle description is valid at low temperatures This suggests that quasiparticle free groundstates so called non Fermi liquids may be detected by examining the symmetry properties of the Peltier tensor