  A diagrammatic approach based on thermal Green function to superconducting
fluctuation transport is reviewed focusing on Hall and Nernst effects. The
treatment of weak magnetic field is carefully discussed within the linear order
perturbation.
  In the Appendix the linear response theory for the DC Hall conductivity of
the Dirac fermion in 2+1 space-time dimensions is reviewed. One focus is the
Chern-Simons effective action for the gauge field. Another is the exact formula
by Ishikawa and Matsuyama.
