@incollection{statphys23_0318,
	title = {Ageing in reaction-diffusion systems},
	address = {Genova, Italy},
	author = {F. Baumann and A. Gambassi and M. Henkel and M. Pleimling and J. Richert},
	booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics},
	editor = {Luciano Pietronero and Vittorio Loreto and Stefano Zapperi},
	month = {9-13 July},
	url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=318},
	year = {2007},
	biburl = {http://www.bibsonomy.org/bibtex/27c79694e052e4ae730305932dc4fd96e/statphys23},
	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).},
	keywords = {ageing directed fluctuation-dissipation percolation ratio reaction-diffusion statphys23 systems topic-4 }
}

@incollection{statphys23_0156,
	title = {Symmetry based determination of space-time functions in nonequilibrium growth processes},
	address = {Genova, Italy},
	author = {M. Pleimling},
	booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics},
	editor = {Luciano Pietronero and Vittorio Loreto and Stefano Zapperi},
	month = {9-13 July},
	url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=156},
	year = {2007},
	biburl = {http://www.bibsonomy.org/bibtex/22c2ce1a0aea8e313891cb0e8e09679fa/statphys23},
	abstract = {We study the space-time correlation and response functions in nonequilibrium growth
processes described by linear stochastic Langevin equations. Exploiting exclusively
the existence of space and time dependent symmetries of the noiseless part of these
equations, we derive expressions for the universal scaling functions of two-time
quantities which are found to agree with the exact expressions obtained from the
stochastic equations of motion. The usefulness of the space-time functions is
illustrated through the investigation of two atomistic growth models, the Family
model and the restricted Family model, which are shown to belong to a unique
universality class in 1+1 and in 2+1 space dimensions. This corrects earlier
studies which claimed that in 2+1 dimensions the two models belong to different
universality classes.\\

A. Roethlein, F. Baumann, and M. Pleimling, Phys. Rev. E {\bf 74}, 061604 (2006)},
	keywords = {equations functions growth langevin nonequilibrium processes space-time statphys23 stochastic topic-4 }
}