1. HOPF BIFURCATION IN DIFFERENTIAL EQUATIONS WITH DELAY FOR TUMOR--IMMUNE SYSTEM COMPETITION MODEL.
- Author
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Yafia, Radouane
- Subjects
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QUALITATIVE chemical analysis , *DIFFERENTIAL equations , *TUMORS , *IMMUNE system , *DYNAMICS , *OSCILLATIONS , *BIFURCATION theory , *SIMULATION methods & models , *LABORATORIES - Abstract
This paper deals with the qualitative analysis of the solutions to a model that refers to the competition between the immune system and an aggressive host such as a tumor. The model which describes this competition is governed by a system of differential equations with one delay. It is shown that the dynamics depends crucially on the time delay parameter. By using the time delay as a parameter of bifurcation, the analysis is focused on the Hopf bifurcation problem to predict the occurrence of a limit cycle bifurcating from the nontrivial steady state. The obtained results depict the oscillations, given by simulations (see [M. Galach, Int. J. Appl. Math. Comput. Sci., 13 (2003), pp. 395–406]), which are observed in reality (see [D. Kirschner and J. C. Panetta, J. Math. Biol., 37 (1998), pp. 235–252]). It is suggested to examine by laboratory experiments how to employ these results for control of tumor growth. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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