INVERSE LANDAU-KHALATNIKOV TRANSFORMATION AND INFRARED CRITICAL EXPONENTS OF (2-DIMENSIONAL QUANTUM ELECTRODYNAMICS(1))

By applying an inverse Landau-Khalatnikov transformation, connecting ( resummed) Schwinger-Dyson treatments in nonlocal and Landau gauges of QED(3), we derive the infrared behaviour of the wave-function renormal ization in the Landau gauge, and the associated critical exponents in the normal phase of the theory (no mass generation). The result agrees with the one conjectured in earlier treatments. The analysis involves an approximation, namely an expansion of the non-local gauge in power s of momenta in the infrared. This approximation is tested by reproduc ing the critical number of flavours necessary for dynamical mass gener ation in the chiral-symmetry-broken phase of QED(3). (C) 1997 Elsevier Science B.V.