TY - JOUR
T1 - Existence of Multiple Positive Periodic Solutions for Second Order Differential Equations
AU - Lü , Yue
AU - Sun , Peng
AU - Cai , Hua
AU - Han , Peishan
JO - Communications in Mathematical Research 
VL - 3
SP - 272
EP - 280
PY - 2021
DA - 2021/05
SN - 32
DO - http://doi.org/10.13447/j.1674-5647.2016.03.09
UR - https://global-sci.org/intro/article_detail/cmr/18899.html
KW - positive periodic solution, multiplicity, differential equation, Krasnoselskii fixed point theorem.
AB - <p style="text-align: justify;">In this paper, we study the existence of multiple positive periodic solutions
for the second order differential equation $$x&#39;&#39;(t) + p(t)x&#39; (t) + q(t)x(t) = f(t, x(t)).$$ By using Krasnoselskii fixed point theorem, we establish some criteria for the existence and multiple positive periodic solutions for this differential equation.</p>