A Dynamically Consistent Nonstandard Difference Scheme for a Discrete-Time Immunogenic Tumors Model

Entropy (Basel). 2022 Jul 7;24(7):949. doi: 10.3390/e24070949.

Abstract

This manuscript deals with the qualitative study of certain properties of an immunogenic tumors model. Mainly, we obtain a dynamically consistent discrete-time immunogenic tumors model using a nonstandard difference scheme. The existence of fixed points and their stability are discussed. It is shown that a continuous system experiences Hopf bifurcation at one and only one positive fixed point, whereas its discrete-time counterpart experiences Neimark-Sacker bifurcation at one and only one positive fixed point. It is shown that there is no chance of period-doubling bifurcation in our discrete-time system. Additionally, numerical simulations are carried out in support of our theoretical discussion.

Keywords: Andronov–Hopf bifurcation; Neimark–Sacker bifurcation; boundedness; control of bifurcation; existence; immunogenic tumors model; linearized stability; nonstandard difference scheme; numerical simulations.

Grants and funding

Spanish Government and European Commission, Grant RTI2018-094336-B-I00 (MCIU/AEI/FEDER, UE); Basque Government, Grant IT1207-19.