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Langevin description of critical phenomena with two symmetric absorbing states
Omar Al Hammal1, Hugues Chaté, Ivan Dornic
1Instituto de Física Teórica y Computacional Carlos I, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain.
Abstract:
On the basis of general considerations, we propose a Langevin equation accounting for critical phenomena occurring in the presence of two symmetric absorbing states. We study its phase diagram by mean-field arguments and direct numerical integration in physical dimensions. Our findings fully account for and clarify the intricate picture known so far from the aggregation of partial results obtained with microscopic models. We argue that the direct transition from disorder to one of two absorbing states is best described as a (generalized) voter critical point and show that it can be split into an Ising and a directed percolation transition in dimensions larger than one.
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