Positive periodic solutions of nonlinear first-order functional difference equations (Q624434)

Summary: We consider the existence, multiplicity, and nonexistence of positive \(T\)-periodic solutions for the difference equations \(\Delta x(n)=a(n)g(x(n))x(n)-\lambda b(n)f(x(n-\tau(n)))\), and \(\Delta x(n)+a(n)g(x(n))x(n)=\lambda b(n)f(x(n-\tau(n)))\), where \(a,b:\mathbb Z\to [0,\infty)\) are \(T\)-periodic, \(\tau:\mathbb Z\to\mathbb Z\) is \(T\)-periodic.