MULTIEXISTENCE OF SLOWLY OSCILLATING PERIODIC-SOLUTIONS FOR DIFFERENTIAL-DELAY EQUATIONS

This paper presents a checkable condition on the function f such that the differential delay equation x(t) = - f(x(t-1)) has at least n distinct slowly oscillating periodic solutions, where n is any natural number or infinity, As an example, an equation is demonstrated to satisfy the condition proposed for n = +infinity, and therefore, it has infinitely many slowly oscillating periodic solutions.