On fixed points of strictly positive stochastic operators on a one-dimensional simplex
https://doi.org/10.26907/2949-3919.2026.2.118-133
Abstract
A class of strictly positive stochastic operators of degree n acting on a one-dimensional simplex is investigated. The main focus is on the problem of the number of fixed points of such operators. It is shown that this problem reduces to studying the number of roots of the corresponding degree n polynomial on the interval (0,1). The existence of at least one fixed point is proved for arbitrary n.
For the quadratic case (n = 2), the uniqueness of the fixed point is established. For a cubic operator (n = 3), conditions for the existence of one, two, or three fixed points are obtained. For a quartic operator (n = 4), criteria determining the number of fixed points are proved in terms of the operator’s parameters.
Keywords
About the Authors
Sh. D. NodirovUzbekistan
Shohruh Dilmurodovich Nodirov,
17, Kuchabag str., Karshi, 180119;
18, Kremlyovskaya str., Kazan 420008 (Russia).
Yu. Kh. Eshkabilov
Uzbekistan
Yusup Khalbayevich Eshkabilov,
17, Kuchabag str., Karshi, 180119.
References
1. Y.I.Lyubich, Mathematical structures in population genetics, Springer-Verlag, Berlin, 1992.
2. F.A.Shahidi, Doubly stochastic operators on a finite-dimensional simplex, Siberian Math. J. 50 (2), 368–372 (2009). https://doi.org/10.1007/s11202-009-0042-3
3. R.Ganikhodzhaev, F.Mukhamedov, U.Rozikov, Quadratic stochastic operators and processes: results and open problems, Infin. Dimens. Anal. Quantum Probab. Relat. Top. 14 (2), 279–335 (2011). https://doi.org/10.1142/S0219025711004365
4. J.N.Jumayev, Criterion for the preservation of the one-dimensional simplex by a cubic operator, Uzbek Math. J. 68 (4), 85–95 (2024). https://doi.org/10.29229/uzmj.2024-4-9
5. J.N.Jumayev, A sufficient condition for a cubic operator to preserve a simplex, J. Sib. Fed. Univ. Math. Phys. 18 (5), 663–673 (2025). URL: https://www.mathnet.ru/rus/jsfu1278
6. U.U.Jamilov, A.Yu.Khamraev, M.Ladra, On a Volterra cubic stochastic operator, Bull. Math. Biol. 80 (2), 319–334 (2018). https://doi.org/10.1007/s11538-017-0376-0
7. A.Yu.Khamraev, J.N.Jumayev, Dynamics of a cubic stochastic operator with one discontinuity point, Uzbek Math. J. 69 (1), 79–86 (2025). https://doi.org/10.29229/uzmj.2025-1-8
8. A.Yu.Khamraev, N.P.Makhmatkobilov, On the dynamics of a quasi-strictly non-Volterra cubic stochastic operator, JCAM 15 (1), 1–9 (2025). https://doi.org/10.62476/jcam.151.1
9. Yu.Kh.Eshkabilov, Sh.D.Nodirov, F.H.Haydarov, Positive fixed points of quadratic operators and Gibbs measures, Positivity 20 (4), 929–943 (2016). https://doi.org/10.1007/s11117-015-0394-9
10. Yu.Kh.Eshkabilov, Sh.D.Nodirov, Positive fixed points of cubic operators on R2 and Gibbs measures, J. Sib. Fed. Univ. Math. Phys. 12 (6), 663–673 (2019). https://doi.org/10.17516/1997-1397-2019-12-6-663-673
11. Yu.Kh.Eshkabilov, Sh.D.Nodirov, Positive fixed points of Hammerstein integral operators with degenerate kernel, Uchenye Zapiski Kazanskogo Universiteta. Seriya Fiziko-Matematicheskie Nauki 166 (3), 437–449 (2024). [in Russian]. https://doi.org/10.26907/2541-7746.2024.3.437-449
12. V.V.Prasolov, Polynomials, Springer-Verlag, Berlin, 2004. https://doi.org/10.1007/978-3-642-03980-5
13. R.Bürger, The mathematical theory of selection, recombination, and mutation, John Wiley & Sons, Ltd., Chichester, 2000.
14. W.J.Ewens, Mathematical population genetics. I. Theoretical introduction, Springer-Verlag, New York, 2004. https://doi.org/10.1007/978-0-387-21822-9
15. S.P.Otto, J.Whitton, Polyploid incidence and evolution, Annu. Rev. Genet. 34, 401–437 (2000). https://doi.org/10.1146/annurev.genet.34.1.401
16. B.S.Baratov, U.U.Jamilov, On separable cubic stochastic operators, Qual. Theory Dyn. Syst. 23 (2), paper no. 93 (2024). https://doi.org/10.1007/s12346-023-00950-5
17. B.S.Baratov, The dynamics of a separable cubic operator, Uzbek Math. J. 68 (2), 27–41 (2024). https://doi.org/10.29229/uzmj.2024-2-4
Review
For citations:
Nodirov Sh.D., Eshkabilov Yu.Kh. On fixed points of strictly positive stochastic operators on a one-dimensional simplex. Mathematics and Theoretical Computer Science. 2026;4(2):118-133. (In Russ.) https://doi.org/10.26907/2949-3919.2026.2.118-133
JATS XML







