具变时滞Holling功能反应的维Lotka-Volterra系统的正周期解
2016-10-14任睿超刘小刚
任睿超,刘小刚
具变时滞Holling功能反应的维Lotka-Volterra系统的正周期解
任睿超[1],刘小刚
(西北大学现代学院 基础部,陕西 西安710130)
利用Mawhin重合度定理讨论了一类带Holling功能反应项的变时滞维Lotka-Volterra竞争模型正周期解的存在性,给出了与变时滞无关的充分条件,改进了现有的结论.
Holling功能反应;正周期解;Mawhin重合度定理
1引言及预备知识
竞争种群动力学模型中,Lotka-Volterra系统已被众学者广泛研究,但大都停留在常时滞或低维单变时滞阶段,而高维多变时滞系统仅被少数学者研究,尤其是带有Holling功能反应的竞争模型,很多结论尚未完善.在最新研究中,文献[1-7]用Mawhin重合度定理讨论了不同情况下维非自治生物种群模型的正周期解的存在性,得到了一些新的结论.
引理1[1]93若是的反函数,则也是严格正的周期连续函数.
引理2(Mawhin重合度定理)[8]设,是Banach空间,是指标为0的Fredholm映射,在上为紧的,是中的任意有界开集,且满足
2主要结果及证明
定理若系统(1)满足:
同理
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[8] Gaines R E,Mawhin J L.Coincidence Degree and Nonlinear Differential Equations[M].Berlin:Springer-Verlay,1977
Positive periodic solution ofdimensional Lotka-Volterra system with multiple varying delays and Holling function response
REN Rui-chao,LIU Xiao-gang
(Department of Basic Course,Modern College of Northwest University,Xi′an 710130,China)
The existence of positive periodic solutions of a class variable delay Lotka-Volterra competition model with Holling functional response was discussed by using Mawhin's coincidence degree theorem,and time varying delay independent sufficient conditions was given,the existing conclusions was improved.
Holling functional response;positive periodic solution;Mawhin coincidence degree theorem
O175.12
A
10.3969/j.issn.1007-9831.2016.04.001
2015-12-28
2014年陕西省教育厅专项科研计划项目(14JK2146)
任睿超(1985-),男,陕西西安人,讲师,硕士,从事微分方程与动力系统研究.E-mail:rrc8512@163.com
1007-9831(2016)04-0001-04