A coupled Gompertz-like system of delay differential equations is considered. We prove the existence of T-periodic solutions under resonance assuming a Lazer–Leach type condition.

A well-known result by Lazer and Leach establishes that if g: R → R is continuous and bounded with limits at infinity and m ε2 ℕ, then the resonant periodic problem u" + m2u + g(u) = p(t), u(0)-u(2π) = u'(0)-u'(2π) = 0 ...

The characteristics of parks (availability, accessibility, conservation, quality, safety, etc.) are important predictors of their use for physical activity practices. The aim of this study was to verify the association ...