{ "id": "1406.1742", "version": "v2", "published": "2014-06-06T17:08:46.000Z", "updated": "2014-12-25T10:26:46.000Z", "title": "Sharp asymptotics for the quasi-stationary distribution of birth-and-death processes", "authors": [ "J. -R. Chazottes", "P. Collet", "S. Méléard" ], "comment": "48 pages, corrected typos, more details. To appear in Probab. Th. & Rel. Fields (2015)", "categories": [ "math.PR", "q-bio.PE" ], "abstract": "We study a general class of birth-and-death processes with state space $\\mathbb{N}$ that describes the size of a population going to extinction with probability one. This class contains the logistic case. The scale of the population is measured in terms of a `carrying capacity' $K$. When $K$ is large, the process is expected to stay close to its deterministic equilibrium during a long time but ultimately goes extinct. Our aim is to quantify the behavior of the process and the mean time to extinction in the quasi-stationary distribution as a function of $K$, for large $K$. We also give a quantitative description of this quasi-stationary distribution. It turns out to be close to a Gaussian distribution centered about the deterministic long-time equilibrium, when $K$ is large. Our analysis relies on precise estimates of the maximal eigenvalue, of the corresponding eigenvector and of the spectral gap of a self-adjoint operator associated with the semigroup of the process.", "revisions": [ { "version": "v1", "updated": "2014-06-06T17:08:46.000Z", "comment": "44 pages", "journal": null, "doi": null }, { "version": "v2", "updated": "2014-12-25T10:26:46.000Z" } ], "analyses": { "keywords": [ "quasi-stationary distribution", "birth-and-death processes", "sharp asymptotics", "deterministic long-time equilibrium", "maximal eigenvalue" ], "note": { "typesetting": "TeX", "pages": 48, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1406.1742C" } } }