{ "id": "1802.09440", "version": "v1", "published": "2018-02-26T16:36:55.000Z", "updated": "2018-02-26T16:36:55.000Z", "title": "Reaction-diffusion on the fully-connected lattice: probability distributions and extreme value statistics for $A+B\\rightarrow$ Ø", "authors": [ "Loïc Turban" ], "comment": "28 pages, 16 figures. Continuation of arXiv:1711.01248", "categories": [ "cond-mat.stat-mech" ], "abstract": "We study the two-species diffusion-annihilation process, $A+B\\rightarrow$ \\O, on the fully-connected lattice. Probability distributions for the number of particles and the reaction time are obtained for a finite-size system using a master equation approach. Mean values and variances are deduced from generating functions. When the reaction is far from complete, i.e., for a large number of particles of each species, mean-field theory is exact and the fluctuations are Gaussian. In the scaling limit the reaction time displays extreme-value statistics in the vicinity of the absorbing states. A generalized Gumbel distribution is obtained for unequal initial densities, $\\rho_A>\\rho_B$. For equal or almost equal initial densities, $\\rho_A\\simeq\\rho_B$, the fluctuations of the reaction time near the absorbing state are governed by a probability density involving derivatives of $\\vartheta_4$, the Jacobi theta function.", "revisions": [ { "version": "v1", "updated": "2018-02-26T16:36:55.000Z" } ], "analyses": { "keywords": [ "extreme value statistics", "probability distributions", "fully-connected lattice", "reaction time displays extreme-value statistics", "reaction-diffusion" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable" } } }