Marginal Fermi Liquid Theory and Renormalization Effects
Marginal Fermi liquid theory proposed by Varma et al. is based on an assumption concerning the imaginary part of the polarization part. We investigate the consequences of this assumption paying full respect to the Ward-Takahashi identity, and find that the vertex corrections are of vital importance. Our result at the low-energy region is that Varma et al.’s assumption does not break the Fermi-liquid picture, as long as the low-energy excitations are concerned.
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- 3.This problem has once been considered by Engelbrecht et al. [J.R. Engelgrecht and M. Randeria Phys. Rev. Lett. 65, 1032 (1990)], in a two dimensional Fermi gas with an arbitrary short-range repulsive force. We reconsidered the singularity of the vertex part because of recent interest in MFL theory [Ref.1].Google Scholar
- 4.See, for example, Bjorken and Drell, Relativistic Quantum Fields ( Mc Graw-Hill, New york, (1965) ) Chapter 18.Google Scholar