Existence of positive periodic solutions for neutral logarithmic population model with multiple delays.
The authors study the existence of positive periodic solutions for a neutral delay logarithmic population model with multiple delays of the form \[ {dN\over dt}= N(t)\Biggl[r(t)- \sum^N_{j=1} a_i(t)\ln N(t- \sigma_i(t))- \sum^m_{j=1} b_j(t){d\over dt}\ln N(t-\tau_j(t))\Biggr],\tag{1} \] with \(\sigma_j(t)\geq 0\) and \(\tau_j(t)\geq 0\). The goal of this paper is to establish some criteria guaranteeing the existence of positive periodic solutions of (1). Under some suitable assumptions on the data of (1), the authors obtain a new existence result by using an abstract continuation theorem for \(k\)-set contraction and some other analytic techniques.
neutral delay logarithmic population model
scientific article; zbMATH DE number 2062742