%0 Book Section %1 statphys23_0318 %A Baumann, F. %A Gambassi, A. %A Henkel, M. %A Pleimling, M. %A Richert, J. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K ageing directed fluctuation-dissipation percolation ratio reaction-diffusion statphys23 systems topic-4 %T Ageing in reaction-diffusion systems %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=318 %X The investigation of ageing phenomena in critical reaction-diffusion systems, like for instance the (fermionic) contact process (directed percolation), has started only recently 1,2. To some surprise it was found that the ageing exponents $a$ and $b$, that describe the scaling behaviour of the autoresponse and of the autocorrelation, are not equal, in contrast to critical systems with detailed balance where the identity $a=b$ holds. As a consequences the definition of the fluctuation-dissipation ratio must differ in these systems from that used in critical magnetic systems. In this contribution we first look at the contact process from a field-theoretical point of view 3, confirming the above result that a and b do not agree. We then suggest an interpretation of the modified definition of the flucutation-dissipation ratio (which was already proposed in 2) for this specific system. We also look at a different type of reaction-diffusion system which allows for an exact solution 4. Also in this case, the above inequality of a and b is confirmed, but the relation between them is not identical to the relation found for the critical contact process. \\ 1) T. Enss, M. Henkel, A. Picone, U. Schollwoeck, J. Phys. A: Math. Gen. 37, 10479.\\ 2) J.J. Ramasco, M. Henkel, M.A. Santos, and C.A. da Silva Santos, J. Phys A: Math. Gen. 37, 10497.\\ 3) F. Baumann and A. Gambassi, J. Stat. Mech. P01002 (2007).\\ 4) F. Baumann, M. Henkel, M. Pleimling, and J. Richert, J.Phys. A: Math. Gen. 38, 6623 (2005).

@incollection{statphys23_0318, abstract = {The investigation of ageing phenomena in critical reaction-diffusion systems, like for instance the (fermionic) contact process (directed percolation), has started only recently [1,2]. To some surprise it was found that the ageing exponents $a$ and $b$, that describe the scaling behaviour of the autoresponse and of the autocorrelation, are not equal, in contrast to critical systems with detailed balance where the identity $a=b$ holds. As a consequences the definition of the fluctuation-dissipation ratio must differ in these systems from that used in critical magnetic systems. In this contribution we first look at the contact process from a field-theoretical point of view [3], confirming the above result that a and b do not agree. We then suggest an interpretation of the modified definition of the flucutation-dissipation ratio (which was already proposed in [2]) for this specific system. We also look at a different type of reaction-diffusion system which allows for an exact solution [4]. Also in this case, the above inequality of a and b is confirmed, but the relation between them is not identical to the relation found for the critical contact process. \\ 1) T. Enss, M. Henkel, A. Picone, U. Schollwoeck, J. Phys. A: Math. Gen. {\bf 37}, 10479.\\ 2) J.J. Ramasco, M. Henkel, M.A. Santos, and C.A. da Silva Santos, J. Phys A: Math. Gen. {\bf 37}, 10497.\\ 3) F. Baumann and A. Gambassi, J. Stat. Mech. P01002 (2007).\\ 4) F. Baumann, M. Henkel, M. Pleimling, and J. Richert, J.Phys. A: Math. Gen. {\bf 38}, 6623 (2005).}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Baumann, F. and Gambassi, A. and Henkel, M. and Pleimling, M. and Richert, J.}, biburl = {https://www.bibsonomy.org/bibtex/27c79694e052e4ae730305932dc4fd96e/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {807591247c071e38b6806035c5653241}, intrahash = {7c79694e052e4ae730305932dc4fd96e}, keywords = {ageing directed fluctuation-dissipation percolation ratio reaction-diffusion statphys23 systems topic-4}, month = {9-13 July}, timestamp = {2007-06-20T10:16:17.000+0200}, title = {Ageing in reaction-diffusion systems}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=318}, year = 2007 }