Stability analysis of delay induced tumor and immune system interaction model

Abstract

This paper consists of interactions among T-helper cells (resting cells), Cytotoxic-T lymphocytes (hunting cells) and tumor cells with time delay.  Stability analysis of equilibrium points and existence of hopf bifurcation is studied. Time delay is utilized as bifurcation parameter. Numerical simulations depict the dynamical performance of the system with different time delay values, which illustrate the phenomenon of long term tumor decline.