Evans, T. S.Gómez Nicola, ÁngelRivers, R. JSteer, D. A.2023-06-202023-06-202003-03-310550-321310.1016/S0550-3213(02)01145-8https://hdl.handle.net/20.500.14352/51404© 2003 Elsevier Science B.V.. R.R. and T.S.E. thank PPARC for financial support. R.R., T.S.E. and D.A.S. thank the Universidad Complutense of Madrid for hospitality and financial support, the ESF for support through its COSLAB programme, and the Rockefeller Foundation at Bellagio for hospitality, where this work was completed. T.S.E. is grateful to CERN for a Visiting Fellowship during which part of this work was done. D.A.S. is grateful to the University of Geneva where part of this work was also done. All the authors thank the University of Salerno, in particular through the ERASMUS/SOCRATES programme, for hosting some of our discussions. A.G.N. thanks financial support from the Spanish CICYT project FPA2000-0956.The conductivity of a finite temperature (1 + 1)-dimensional fermion gas described by the massive Thirring model is shown to be related to the retarded propagator of the dual boson sine-Gordon model. Duality provides a natural resummation which resolves infra-red problems, and the boson propagator can be related to the fermion gas at non-zero temperature and chemical potential or density. In addition, at high temperatures, we can apply a dimensional reduction technique to find resummed closed expressions for the boson self-energy and relate them to the fermion conductivity. Particular attention is paid to the discussion of analytic continuation and to the link with integrable field theories. The resummation implicit in duality provides a powerful alternative to the standard diagrammatic evaluation of transport coefficients at finite temperature.engjournal articlehttp://dx.doi.org/10.1016/S0550-3213(02)01145-8http://www.sciencedirect.comopen access51-73Quantum-field-theoryHot gauge-theoriesMassive thirring modelsSine-gordonDimensional reductionQuantized conductanceExpectation valuesLuttinger liquidGreen-functionsPoint contactsFísica-Modelos matemáticosFísica matemática