TY - JOUR

T1 - A note on positive periodic solutions of delayed differential equations

AU - Jin, Zhi Long

AU - Wang, Haiyan

N1 - Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.

PY - 2010/5

Y1 - 2010/5

N2 - We consider the existence of positive ω-periodic solutions for the periodic equation x′ (t) = a (t) ex (t) x (t) - λ b (t) f (x (t - τ (t))), where a, b ∈ C (R, [0, ∞)) are ω-periodic, ∫0ω a (t) d t > 0, ∫0ω b (t) d t > 0, f ∈ C ([0, ∞), [0, ∞)), and f (u) > 0 for u > 0, τ (t) is a continuous ω-periodic function.

AB - We consider the existence of positive ω-periodic solutions for the periodic equation x′ (t) = a (t) ex (t) x (t) - λ b (t) f (x (t - τ (t))), where a, b ∈ C (R, [0, ∞)) are ω-periodic, ∫0ω a (t) d t > 0, ∫0ω b (t) d t > 0, f ∈ C ([0, ∞), [0, ∞)), and f (u) > 0 for u > 0, τ (t) is a continuous ω-periodic function.

KW - Existence

KW - Fixed index theorem

KW - Positive periodic solution

UR - http://www.scopus.com/inward/record.url?scp=77949485003&partnerID=8YFLogxK

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U2 - 10.1016/j.aml.2010.01.015

DO - 10.1016/j.aml.2010.01.015

M3 - Article

AN - SCOPUS:77949485003

VL - 23

SP - 581

EP - 584

JO - Applied Mathematics Letters

JF - Applied Mathematics Letters

SN - 0893-9659

IS - 5

ER -