Unlimited Growth?

Noise-driven unlimited population growth.

Demographic noise causes unlimited population growth in a broad class of models which, without noise, would predict a stable finite population. We study this effect on the example of a stochastic birth-death model which includes immigration, binary reproduction, and death. The unlimited population growth proceeds as an exponentially slow decay of a metastable probability distribution (MPD) of t...

Criterion of unlimited growth of critical multidimensional stochastic models

where {Fn, n ∈ N}, is the natural filtration associated to (Xn). We assume that X0 ∈ R d + and that random vectors ξn are such that for all n, Xn ∈ R d + almost surely. The Perron-Frobenius Theorem [10, pp. 3-4] states that M has a positive Perron root ρ. We call Xn “subcritical” if ρ < 1, “supercritical” if ρ > 1 and “critical” if ρ = 1. In the “subcritical” case, one has P(‖Xn‖ → ∞) = 0 becau...

Pinball Dynamics: Unlimited Energy Growth in Switching Hamiltonian Systems

A family of discontinuous symplectic maps arising naturally in the study of nonsmooth switched Hamiltonian systems is considered. This family depends on two parameters and is a canonical model for the study of bounded and unbounded behavior in discontinuous area-preserving transformations due to nonlinear resonances. This paper provides a general description of the map and a construction of non...

Distrib Unlimited

Darwin unlimited

The largest collection of Darwin's writings ever published appeared last month on the website The Complete Works of Charles Darwin Online (http://darwin-online.org.uk). Never before has so much Darwin material, and so many rare and widely dispersed items, been brought together in one place and made available free of charge. The site currently offers more than 50,000 pages of searchable text and...