P000054
Four limit cycles in three-dimensional Lotka-Volterra competitive systems for classes 28, 30 and 31 in Zeeman's classification
*Mingzhi Hu (School of Mathematical Sciences, Sichuan Normal University)
Zhengyi Lu (School of Mathematical Sciences, Sichuan Normal University)
Yong Luo (College of Mathematics and Physics, Wenzhou University)
The three-dimensional Lotka-Volterra competitive systems with four limit cycles are constructed for classes 28, 30 and 31 in Zeeman's classification, together with the results from Gyllenberg, Yan and Wang (2009) for class 27, from Wang, Huang and Wu (2011) for classes 28 and 29 and Yu, Han and Xiao (2016) for class 26 which indicate that for each class among classes 26$-$31, there exist systems with at least four limit cycles. This gives a partial answer to a conjecture proposed in Hofbauer and So (1994) as well as in Yu, Han and Xiao (2016).