Alonso, J. L.Fernández Pérez, Luis AntonioMartín Mayor, Víctor2023-06-202023-06-202000-05-111) F. Karsch, M-P. Lombardo (Eds.), QCD at Finite Barion Density, Nucl. Phys. A, 642, 1998 Proc. Supp. 1-2. 2) F. Karsch, J.B. Kogut, H.W. Wyld, Nucl. Phys. B, 280 [FS18], 1987, p. 289 -- S.J. Hands, A. Kocić, J.B. Kogut, Nucl. Phys. B, 390, 1993, 355 -- S.J. Hands, S. Kim, J.B. Kogut, Nucl. Phys. B, 442, 1995, 364 -- I. Barbour, S. Hands, J.B., Kogut, M.-P. Lombardo, S. Morrison, Nucl. Phys. B, 557, 1999, 327. 3) M.P. Lombardo, hep-latr9907025 -- S. Hands, J.B. Kogut, M.P. Lombardo, S. Morrison, Nucl. Phys. B, 558, 1999, 327. 4) W. Kohn, Phys. Rev., 133, 1964, A171. 5) K.G. Wilson, Phys. Rev. D, 14, 1974, 2455. 6) K.G. Wilson. Quarks and Strings on the Lattice, in New Phenomena in subnuclear Physics (A. Zichichi Ed., Plenum Press, New York 1977). 7) P. Hasenfratz, F. Karsch, Phys. Lett. B, 125, 1983, 308. 8) J.B. Kogut, H. Matsuoka, M. Stone, H.W. Wyld, S. Shenker, J. Shigemitsum, D.K. Sinclair, Nucl. Phys. B, 225, [FS9], 1983, p. 93. 9) I. Bender, H.J. Rothe, I.O. Stomatescu, W. Wetzel, Z. Phys. C, 58, 1993, 333. 10) I. Montvay, G. Munster, Quantum Fields on a Lattice (Cambridge Univ. Press. 1994). 11) R.V. Gavai, Phys. Rev. D, 32, 1985, 519. 12) N.W. Ashcroft, N.D. Mermin, Solid State Physics, Saunders College Publishing, 1976. 13) G. Martinelli, G. Parisi, R. Petronzio, F. Rapuano, Phys. Lett. B, 116, 1982, 434 -- C. Bernard, T. Draper, K. Olynyk, M. Rushton, Phys. Rev. Lett., 49, 1982, 1076 -- J. Ambjorn, V.K. Mitryushkin, V.G. Bornyakov, A.M. Zadorozhnyi, Phys. Lett. B, 225, 1989, 153 -- M. Lüscher, P. Weisz, R. Sommer, U. Wolff, Nucl. Phys. B, 389, 1993, 247.0370-269310.1016/S0370-2693(00)00398-1https://hdl.handle.net/20.500.14352/60067© 2000 Elsevier Science B.V. This work was triggered during a discussion with F. Guinea to whom we are indebted for many suggestions, discussions and bibliographical help. The numerical calculations have being carried-out in the RTNN machines at the universities of Zaragoza and Complutense de Madrid. This work has been partially supported by CICYT, contracts AEN97- 1680,1693,1708.We study the linear response to an external electric field of a system of fermions in a lattice at zero temperature. This allows to measure numerically the Euclidean conductivity which turns out to be compatible with an analytical calculation for free fermions. The numerical method is generalizable to systems with dynamical interactions where no analytical approach is possible.engjournal articlehttp://doi.org/10.1016/S0370-2693(00)00398-1http://www.sciencedirect.com/open access51-73Gross-Neveu modelChiral-symmetry restorationTemperature.Física (Física)Física-Modelos matemáticos22 Física