Research in the theory of nonlinear boundary problems for ordinary differential equations, theory of oscillations, asymmetric problems, qualitative behavior of solutions of nonlinear differential equations, approximation of solutions, calculus of variations, problems from applications, spectral problems, analysis of three dimensional systems

• Dr.habil.math., University of Latvia, Riga, Latvia
  Dissertation: Estimations of the number of solutions of nonlinear  boundary value problems.

• Ph.D. (Candidate of Science), Differential Equations, Belourussian State University, Minsk
  Dissertation: On some class of boundary value problems for a system of the first order ordinary differential equations.
  Advisor: Prof. Yurii Klokov

• Graduated from Latvian State University, Faculty of Physics and Mathematics, Riga, Latvia
  Thesis: Properties of Operators in Hilbert Spaces.
  Advised by Gennadiy Laptev

• Professor at the Daugavpils University from 1999.
• Courses taught: Basics of Optimization, Mathematical Modelling and Differential Equations
• Coordinator of Doctoral studies in Mathematics (Daugavpils University) from 2002

• Fundamental and applied research project of the Latvian Council of Science "Analysis of complex dynamical systems in fluid mechanics and heat transfer", Researcher,  lzp-2021/1-0076.

• Latvian Council of Science,  Project Nr. 09.1220 Contemporary Methods of Analyzing Dynamical Systems,  Head of the project, 2009-

• Latvian Council of Science,  Project Nr. 05.1531 Nonlinear Boundary Value Problems for Ordinary Differential Equations, Head of the project, 2005-2008.

• Latvian Council of Science,  Project  Nr. 01.0356  Nonlinear Boundary Value Problems for Ordinary Differential Equations, Head of the project, 2001-2004.

• A. Gritsans and F. Sadyrbaev, On differential equations with exponential nonlinearities, Applied Numerical Mathematics, Vol. 207, 2025, pp. 558-568.

• A. Gritsans, A. Kolyshkin, F. Sadyrbaev, and I. Yermachenko, Effect of rotation of the boundaries on the stability of a flow caused by a nonlinear heat source, Proceedings of the 9th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2024, June 3-7, 2024, Lisbon, Portugal), 2024, pp. 1-12.

• O. Kozlovska, F. Sadyrbaev, and I. Samuilik, A New 3D Chaotic Attractor in Gene Regulatory Network, Mathematics 2024, 12(1), 100.

• S. Atslega, O. Kozlovska, and F. Sadyrbaev, On Period Annuli and Induced Chaos, WSEAS Transactions on Systems, Vol. 23, Art. #17, 2024, pp. 149-156.

• O. Kozlovska and F. Sadyrbaev, In search of chaos in genetic systems,  Chaos Theory and Applications, Vol. 6, No. 1, 2024, pp. 13-18.

• D. Ogorelova, F. Sadyrbaev, and I. Samuilik, On Targeted Control over Trajectories of Dynamical Systems Arising in Models of Complex Networks, Mathematics 2023, 11(9), 2206.

• F. Sadyrbaev and I. Samuilik, On the hierarchy of attractors in dynamical models of complex networks, AIP Conf. Proc. 2849, 120005 (2023).

• A. Kirichuka and F. Sadyrbaev, On Boundary Value Problems for Liénard Type Equation, WSEAS Transactions on Systems and Control, Vol. 18, Art. #47, 2023, pp. 437-443.

• F. Sadyrbaev and I. Samuilik, I. From Duffing Equation to Bio-oscillations. In: Pinto, C.M., Ionescu, C.M. (eds) Computational and Mathematical Models in Biology. Nonlinear Systems and Complexity, Springer, Cham, Vol. 38, 2023, pp. 159–182.

• O. Kozlovska and F. Sadyrbaev, On Attractors in Systems of Ordinary Differential Equations Arising in Models of Genetic Networks, Vibroengineering PROCEDIA, Vol. 49, 2023, pp. 136-140.

• F. Sadyrbaev, Modeling the evolution of complex networks arising in applications, Chapter 5 of "Human-Assisted Intelligent Computing", IOP Publishing, 2023, pages 5-1 to 5-22.

• F. Sadyrbaev, On solutions of the third-order ordinary differential equations of Emden-Fowler type, Dynamics, Vol. 3, No. 3, 2023, pp. 550-562.

• D. Ogorelova, F. Sadyrbaev, and I. Samuılık, On attractors in dynamical systems modeling genetic networks, Advances in the Theory of Nonlinear Analysis and its Application, Vol. 7, No. 2, 2023, pp. 486-498.

• F. Sadyrbaev, V. Sengileyev, and A. Silvans, On coexistence of inhibition and activation in genetic regulatory networks, AIP Conf. Proc. 2849, 120004 (2023).

• S. Atslega and F. Sadyrbaev, On the period-amplitude relation by reduction to Liénard quadratic equation, WSEAS Transactions on Mathematics, Vol. 22, Art. #34, 2023, pp. 285-291.

• A. Kirichuka and F. Sadyrbaev, Multiple solutions for Liénard type generalized equations, WSEAS Transactions on Systems, Vol. 22, Art. #58, 2023, pp. 578-583.

• I. Samuilik, F. Sadyrbaev, and S. Atslega, On mathematical models of artificial neural networks,  Proceedings of 22nd International Scientific Conference  "Engineering for Rural Development" (May 24-25, Jelgava, Latvia), 2023, pp. 45-50.

• F. Sadyrbaev and O. Kozlovska, Example of chaotic behavior in systems of ordinary differential equations arising in modeling of gene regulatory networks, Selected Papers of the XX International Scientific Conference "Dynamical System Modeling and Stability Investigation" (DSMSI-2023, Kyiv, Ukraine, December 20-21, 2023), Volume 2: Computer Applied Mathematics, 2023, pp. 85-89.

• A. Gritsans, A. Kolyshkin, F. Sadyrbaev, and I. Yermachenko, On the stability of a convective flow with nonlinear heat sources, Mathematics, 11(18): 3895, 2023.

• A. Gritsans, V. Koliskina, A. Kolyshkin, and F. Sadyrbaev, Linear stability of a combined convective flow in an annulus, Fluids, 8(4):130, 2023.

• A. Kirichuka and F. Sadyrbaev, Boundary value problems for Liénard-type equations with quadratic dependence on the "velocity",  Abstract and Applied Analysis, Vol. 2022 (2022), Article ID 9228511, 12 pages.

• I. Samuilik and F. Sadyrbaev, On a system without critical points arising in heat conductivity theory, WSEAS Transactions on Heat and Mass Transfer, Vol. 17, 2022, pp. 151-160.

• F. Sadyrbaev, On Nehari solutions, Journal of Computational Mathematica, Vol. 6, No. 1, 2022, pp. 233-242.

• I. Samuilik, F. Sadyrbaev, and D. Ogorelova, Mathematical modeling of three - dimensional genetic regulatory networks using logistic and Gompertz functions, WSEAS Transactions on Systems and Control, Vol. 17, 2022, pp. 101-107.

• I. Samuilik, F. Sadyrbaev, and S. Atslega, Mathematical modelling of nonlinear dynamic systems, Proceedings of 21st International Scientific Conference "Engineering for Rural Development" (May 25-27, Jelgava, Latvia), 2022, pp. 172-178.

• A. Kirichuka, F. Sadyrbaev, On the number of solutions for a certain class of nonlinear second-order boundary-value problems, Journal of Mathematical Sciences, Vol. 257, 2021, pp. 31–40.

• D.A. Ogorelova, F.Zh. Sadyrbaev, Gompertz function in the model of gene regulatory networks, Proceedings of the International Conference on Mathematical Modelling in Applied Sciences — ICMMAS'19. Belgorod, August 20–24, 2019, Itogi Nauki i Tekhniki. Ser. Sovrem. Mat. Pril. Temat. Obz., Vol. 195, VINITI, Moscow, 2021, pp. 88–96.

• A. Gritsans, V. Koliskina, A. Kolyshkin, and F. Sadyrbaev, On the stability of a steady convective flow in a vertical layer of a chemically reacting fluid, in: 9th edition of the International Conference on Computational Methods for Coupled Problems in Science and Engineering (COUPLED PROBLEMS 2021), Vol. IS34 - Multiphysics Problems, 2021, 10 pp.

• A. Gritsans, A. Kolyshkin, D. Ogorelova, F. Sadyrbaev, I. Samuilik, and I. Yermachenko, Solutions of nonlinear boundary value problem with applications to biomass thermal conversion, Proceedings of 20th International Scientific Conference "Engineering for rural development" (May 26-28, Jelgava, Latvia), 2021, pp. 837-842.

• S. Atslega, F. Sadyrbaev, and I. Samuilik, On modelling of complex networks, Proceedings of 20th International Scientific Conference "Engineering for rural development" (May 26-28, Jelgava, Latvia), 2021, pp. 1009-1014.

• I. Samuilik and F. Sadyrbaev, Modelling three dimensional gene regulatory networks, WSEAS Transactions on Systems and Control, Vol. 16, 2021, pp. 755-763.

• I. Samuilik and F. Sadyrbaev, Mathematical modelling of leukemia treatment, WSEAS Transactions on Computers, Vol. 20, 2021, pp. 274-281.

• F. Sadyrbaev, I. Samuilik, and V. Sengileyev, On modelling of genetic regulatory networks, WSEAS Transactions on Electronics, Vol. 12, 2021, Art. #10.

• A. Bogachov and F. Sadyrbaev, On forced vibrations caused by earthquakes, International Journal of Mechanical Engineering, Vol. 6, 2021, pp. 34-37.

• F. Sadyrbaev and S. Atslega, A remark on attracting sets in genetic regulatory networks, AIP Conference Proceedings, Vol. 2293, 090004, 2020.

• S. Atslega and F. Sadyrbaev, On modelling of artificial networks arising in applications, Proceedings of 19th International Scientific Conference Engineering for Rural Development (May 20-22, 2020, Jelgava, Latvia), 2020, 19, pp. 1659-1665.

• F. Sadyrbaev, S. Atslega, and E. Brokan, Dynamical Models of Interrelation in a Class of Artificial Networks. In: Pinelas S., Graef J.R., Hilger S., Kloeden P., Schinas C. (eds) Differential and Difference Equations with Applications. ICDDEA 2019. Springer Proceedings in Mathematics & Statistics, Vol. 333. Springer, Cham, 2020. https://doi.org/10.1007/978-3-030-56323-3_18

• D. Ogorelova, F. Sadyrbaev, and V. Sengileyev, Control in inhibitory genetic regulatory network models, Contemporary Mathematics, Vol. 1, No. 5, 2020, pp. 421-428.

• E. Brokan and F. Sadyrbaev, Remarks on GRN-type systems, 4open, Vol. 3, No. 8, 2020.

• F. Sadyrbaev, Planar differential systems arising in network regulation theory, Advanced Mathematical Models & Applications, Vol. 4, No. 1, 2019, pp. 70-78.  

• A. Gritsans and F. Sadyrbaev, A two-point boundary value problem for third order asymptotically linear systems, Electronic Journal of Qualitative Theory of Differential Equations, No. 28, 2019, 24 pp. pdf  

• A.V. Kirichuka and F.Zh. Sadyrbaev, On the number of solutions for a certain class of nonlinear second-order boundary-value problems, Proceedings of the International Conference on Mathematical Modelling in Applied Sciences ICMMAS-17, St. Petersburg Polytechnic University, July 24-28, 2017, Itogi Nauki i Tekhniki. Ser. Sovrem. Mat. Pril. Temat. Obz., 160, VINITI, Moscow, 2019, pp. 32–41.

• F. Sadyrbaev and E. Brokan, On controllability of nonlinear dynamical network, AIP Conference Proceedings, Vol. 2116, Issue 1, 040005, 2019.

• A. Kirichuka and F. Sadyrbaev, On boundary value problem for equations with cubic nonlinearity and step-wise coefficient, Differential Equations & Applications, Vol. 10, No. 4, 2018, pp. 433-447.

• A. Gritsans, F. Sadyrbaev, and I. Yermachenko, Dirichlet boundary value problem for a system of n second order asymptotically asymmetric differential equations, Electron. J. Differential Equations, Vol. 2018 (2018), No. 35, pp. 1-16.

• E. Brokan and F. Sadyrbaev, Attraction in n-dimensional differential systems from network regulation theory, Mathematical Methods in the Applied Sciences, Vol. 41, No. 17, 2018, pp. 7498-7509.

• E. Brokan and F. Sadyrbaev, Networks Describing Dynamical Systems, Tatra Mountains Mathematical Publications, Vol. 71, Issue 1, 2018, pp. 39–52.

• F. Sadyrbaev, On attracting sets in artificial networks: cross activation, ITM Web Conf., Vol. 16, Article Number 01005, 2018, 3. pp. 

• N. Sveikate and F. Sadyrbaev, On conversion of resonant problem to non-resonant one, Miskolc Mathematical Notes, Vol. 18, No. 2, 2017, 1059-1071.

• E. Brokan and F. Sadyrbaev, Attraction in network describing systems, Proceedings of the 17th International Conference on Computational and Mathematical Methods in Science and Engineering (Costa Ballena, Rota, Cadiz, Spain, 4-8 July, 2017), 2017, 415-418. CMMSE 2017

• F. Sadyrbaev. Note on resonant problems, Proceedings of the 17th International Conference on Computational and Mathematical Methods in Science and Engineering (Costa Ballena, Rota, Cadiz, Spain, 4-8 July, 2017), 2017, 1862-1864. CMMSE 2017

• E. Brokan and F. Sadyrbaev. On attractors in gene regulatory systems. American Institute of Physics Conference Proceedings, 2017, Vol. 1809, 020010. American Institute of Physics

• A. Gritsans, F. Sadyrbaev, and I. Yermachenko. Dirichlet boundary value problem for the second order asymptotically linear system. International Journal of Differential Equations, Vol. 2016 (2016), Article ID 5676217, 12 pp. http://dx.doi.org/10.1155/2016/5676217. Hindawi

• D. Finaskins, E. Brokan, and F. Sadyrbaev. Attracting sets in network regulatory theory. 2016 Advances in Wireless and Optical Communications (RTUWO), 2016, 211 - 215. IEEE Xplore

• E. Brokan and F. Sadyrbaev. On a differential system arising in the network control theory. Nonlinear Analysis: Modelling and Control, Vol. 21, No. 5, 2016, 687–701.

• M. Dobkevich and F. Sadyrbaev. On different type solutions of boundary value problems. Math. Modelling and Analysis, Vol. 21, No. 5,  2016, 659-667.

• S. Atslega, D. Finaskins, and F. Sadyrbaev. On a planar dynamical system arising in the network control theory. Math. Modelling and Analysis, Vol. 21, No. 3,  2016, 385-398.

• S. Atslega and F. Sadyrbaev. Solutions of two-point boundary value problems via phase-plane analysis. E. J. Qualitative Theory of Diff. Equ., Proc. 10'th Coll. Qualitative Theory of Diff. Equ., No. 4, 2016, 1-10. EJQTDE

• F. Sadyrbaev. Oscillatory solutions of boundary value problems. In: Springer Proceedings in Mathematics & Statistics, Vol. 164, S. Pinelas, Z. Dosla, O. Dosly, P.E. Kloeden (Eds.), Differential & Difference Equations and Applications,  2016, 109-117. Springer

• A. Gritsans and F. Sadyrbaev. The Nehari solutions and asymmetric minimizers, in: Proceedings of the 10th AIMS Conference on Dynamical Systems, Differential Equations and Applications (Madrid, Spain, July 7-11, 2014), Discrete and Continuous Dynamical Systems,  2015, Suppl., 562-568. American Institute of Mathematical Sciences

• M. Dobkevich and F. Sadyrbaev. Types and multiplicity of solutions to Sturm–Liouville boundary value problem. Math. Modelling and Analysis, Vol. 20, No. 1,  2015, 1-8.

• A. Kirichuka and F. Sadyrbaev. Multiple positive solutions for the Dirichlet boundary value problems by phase plane analysis. Abstract and Applied Analysis, Vol. 2015 (2015), Article ID 302185, 6 pages doi:10.1155/2015/302185. Hindawi

• A. Gritsans and F. Sadyrbaev. Extension of the example by Moore–Nehari. Tatra Mountains Mathematical Publications, Vol. 63, No. 2.,  2015, 115-127. Tatra Mountains Mathematical Publications  De Gruyter pdf.

• E. Brokan and F. Sadyrbaev. Attracting Sets in Gene Regulatory Systems. In Proceedings of International Conference on Simulation, Modelling and Mathematical Statistics (SMMS 2015), 2015, 135-138. Link

• I. Yermachenko and F. Sadyrbaev. On a problem for a system of two the second order differential equations via the theory of vector fields. Nonlinear Analysis. Modelling and Control, Vol. 20, No. 2, 2015, 175-189.

• M. Dobkevich, F. Sadyrbaev, N. Sveikate, and I. Yermachenko. On types of solutions of the second order nonlinear boundary value problems. Abstract and Applied Analysis, Vol. 2014 (2014), Article ID 594931, 9 pages, http://dx.doi.org/10.1155/2014/594931. Hindawi

• A. Gritsans and F. Sadyrbaev. Unexpected solutions of the Nehari problem. International Journal of Analysis, Vol. 2014 (2014), Article ID 467831, 5 pages doi:10.1155/2014/467831. Hindawi pdf

• N. Sveikate and F. Sadyrbaev. Quasilinearization for resonant boundary-value problems with mixed boundary conditions, Nonlinear Oscillations, Vol. 17, No. 1, 2014, 112-126. Nonlinear Oscillations
  
  N. Sveikate and F. Sadyrbaev. Quasilinearization for resonant boundary-value problems with mixed boundary conditions, Journal of Mathematical Sciences, Vol. 205, No. 6, 2015, 832-847. Springer

• I. Yermachenko and F. Sadyrbaev. Quasilinearization and multiple solutions of the second order nonlinear boundary value problem, Journal of Control Engineering and Technology, Vol. 4, No. 1, 2014, 1-8. EBSCO pdf

• S. Atslega and F. Sadyrbaev. On periodic solutions of Liénard type equations. Math. Modelling and Analysis, Vol. 18, No. 5,  2013, 708-716.

• F. Sadyrbaev. Two-dimensional systems with asymmetric principal part. In: Springer Proceedings in Mathematics & Statistics, Vol. 47, S. Pinelas, M. Chipot, Z. Dosla (Eds.), Contributions from the International Conference on Differential & Difference Equations and Applications,  2013, 99-111. Springer

• A. Gritsans and F. Sadyrbaev. On solvability of boundary value problem for asymmetric differential equation depending on x'. Math. Modelling and Analysis, Vol. 18, No. 2,  2013, 176-190. pdf

• A. Gritsans and F. Sadyrbaev. Boundary value problems for a super-sublinear asymmetric oscillator: exact number of solutions. International Journal of Mathematics and Mathematical Sciences, Vol. 2013 (2013), Article ID 705984, 9 pages doi:10.1155/2013/705984. Hindawi pdf

• I. Yermachenko and F. Sadyrbaev. Quasilinearization technique for Φ-Laplacian type equations. International Journal of Mathematics and Mathematical Sciences, Vol. 2012 (2012), Article ID 975760, 11 pages doi:10.1155/2012/975760. Hindawi

• A. Gritsans and F. Sadyrbaev. Nonlinear problems with asymmetric principal part. Math. Modelling and Analysis, Vol. 17, No. 2,  2012, 217-226. pdf

• Y. Kozmina and  F. Sadyrbaev. On a maximal number of period annuli, Abstract and Applied Analysis, Vol. 2011 (2011), Article ID 393875, 8 pages, doi:10.1155/2011/393875. Hindawi

• A. Gritsans and F. Sadyrbaev. Two-parameter nonlinear oscillations: the Neumann problem. Math. Modelling and Analysis, Vol. 16, No. 1,  2011, 23-38. pdf

• F. Sadyrbaev and N. Sergejeva. On a Fučik type spectral problem for the second order nonlinear differential equation with the integral boundary condition. Communications in Applied Analysis, Vol. 15, No. 2-4,  2011, 557-567. Dynamic Publishers pdf

• S. Atslega and F. Sadyrbaev.  Multiple period annuli in Lienard type equations. Applied Mathematics Letters, Vol. 23, No. 2, 2010, 165–169. Elsevier

• F. Sadyrbaev. Multiplicity in parameter-dependent problems for ordinary differential equations. Mathematical Modelling and Analysis, Vol. 14, No. 4, 2009, 503-514.

• M. Dobkevich and F. Sadyrbaev. Types of solutions and approximation of solutions of second order nonlinear boundary value problems.  In: Amer. Inst. Phys. Conference Proceedings Volume 1168, 260 – 263. Numerical Analysis and applied mathematics: International Conference on Numerical Analysis and Applied Mathematics 2009: Part 2, Rethymno, Crete (Greece), 18 – 22 September 2009. American Institute of Physics

• S. Atslega and F. Sadyrbaev. Multiple positive solutions in the second order autonomous nonlinear boundary value problems. In: American Institute of Physics Conference Proceedings Vol. 1168, 873-876. Numerical Analysis and Applied Mathematics: International Conference on Numerical Analysis and Applied Mathematics 2009, Part 1, Rethymno, Crete (Greece), 18 – 22 September 2009. American Institute of Physics

• S. Atslega and F. Sadyrbaev. Multiple solutions of the second order nonlinear Neumann BVP. Dynamics of Continuous, Discrete and Impulsive Systems (Series A). DCDIS A Supplement dedicated to the 6th International Conference on Differential Equations and Dynamical Systems held in Baltimore, U.S.A., May 22 - 26 - Watam Press, 2009, 100–103.

• A. Gritsans, F. Sadyrbaev, and N. Sergejeva. Two parameter nonlinear eigenvalue problems. Mathematical Models in Engineering, Biology, and Medicine, Proceedings of the International Conference on Boundary Value Problems, American Institute of Physics Conference Proceedings, 2009, Vol. 1124, 185-194. American Institute of Physics

• S. Atslega and F. Sadyrbaev. Period annuli and multiple solutions for two-point BVP. Tatra Mountains Mathematical Publications, Vol. 43, 2009, 11–23. Link

• A. Gritsans and F. Sadyrbaev. Nonlinear spectra: the Neumann problem, Math. Modelling and Analysis, Vol. 14, No. 1,  2009, 33-42. pdf

• I. Yermachenko and F. Sadyrbaev. Multiple solutions of nonlinear boundary value problems for two-dimensional differential systems. Dynamical Systems and Differential Equations.   Proc. of  the 7th AIMS International Conference (Arlington, TX, USA, 2008), DCDS Supplement 2009, 659 - 668. American Institute of Mathematical Sciences

• F. Sadyrbaev and I. Yermachenko. Multiple solutions of two-point nonlinear boundary value problems. Nonlinear Analysis: TMA, Vol. 71, No. 12, 2009, e176 – e185, Proc. WCNA 2008, Orlando FL, USA, 2008. Elsevier

• A. Gritsans and F. Sadyrbaev. On nonlinear Fučik type spectra, Math. Modelling and Analysis, Vol. 13, No. 2,  2008, 203-210. pdf

• A. Gritsans and F. Sadyrbaev. Two-parametric nonlinear eigenvalue problems. E. J. Qualitative Theory of Diff. Equ., Proc. 8'th Coll. Qualitative Theory of Diff. Equ., No. 10, 2008, 1-14. EJQTDE

• F. Sadyrbaev and I. Yermachenko. Types of solutions and multiplicity results for two-point nonlinear boundary value problems. Proceedings of AIMS' Sixth International Conference on Dyn. Systems, Diff. Equations and Applications University of Poitiers, Poitiers, France, June 25 - 28, 2006, Discrete and Continuous Dynamical Systems -  Supplement 2007, American Institute of Mathematical Sciences, 1061-1069. American Institute of Mathematical Sciences

• F. Sadyrbaev and A. Gritsans. Nonlinear spectra for parameter dependent ordinary differential equations. Nonlinear Analysis: Modelling and Control, Vol. 12, No. 2, 2007, 253–267. pdf

• F. Sadyrbaev. Multiplicity of solutions for second order two-point boundary value problems with asymptotically asymmetric nonlinearities at resonance. Georgian Mathematical Journal, Vol. 14, No. 2, 2007, 351–360. De Gruyter

• A. Gritsans and  F. Sadyrbaev. On the Nehari solutions. Proceedings of Equadiff 11, International Conference on Differential Equations. Czecho-Slovak series, Bratislava, July 25-29, 2005. [Part 2] Minisymposia and contributed talks. Comenius University Press, Bratislava, 2007, pp. 437-446. Czech Digital Mathematics Library

• A. Gritsans and F. Sadyrbaev. Characteristic numbers of non-autonomous Emden-Fowler type equations, Math. Modelling and Analysis, Vol. 11, No. 3,  2006, 243-252. pdf

• A. Gritsans and F. Sadyrbaev, On sine and cosine type functions, arising in the theory of nonlinear differential equations, Acta Societatis Mathematicae Latviensis, no. 7, Abstracts of the 6th Latvian Matematical Conference (April 7-8, 2006, Liepaja, Latvia), Liepaja, p. 28, 2006. pdf

• F. Sadyrbaev and I. Yermachenko. Quasilinearization and multiple solutions of the Emden-Fowler type equation.  Mathematical Modelling Analysis, Vol. 10, No. 1, 2005, 41-50.

• F. Sadyrbaev and I. Yermachenko. Types of solutions and multiplicity results for two-point non­linear boundary value problems. Nonlinear Analysis: TMA, Vol. 63, No. 5-7, 2005, e1725 – e1735. Elsevier

• A. Gritsans and F. Sadyrbaev. Characteristic numbers of non-autonomous Emden-Fowler type equations. Proceedings: 10th International Conference "Mathematical Modelling and Analysis 2005'' and 2nd International Conference "Computational Methods in Applied Mathematics'', 403--408, Technika, Vilnius, 2005. pdf

• A. Gritsans and F. Sadyrbaev. Remarks on lemniscatic functions. Acta Universitatis Latviensis, Vol. 688. Mathematics, 2005, 39-50.  pdf dspace.lu.lv

• A. Gritsans and F. Sadyrbaev. The Taylor series expansion coefficients for solutions of the Emden-Fowler type equations, Math. Modelling and Analysis, Vol. 10, No. 3, 2005, 247-256. pdf

• F. Sadyrbaev. Nonlinear boundary value problems of the calculus of variations.  Discrete and Continuous Dynamical Systems - Supplement Volume,  American Institute of Mathematical Sciences, 2003, 770-779. American Institute of Mathematical Sciences

• Yu. Klokov  and F. Sadyrbaev. Sharp conditions for rapid nonlinear oscillations. Nonlinear Analysis: TMA, Vol. 39, No. 39, 2000,  519–533. Elsevier

• Yu. Klokov  and F. Sadyrbaev. Rapid oscillations in sublinear problems. Funkcialaj Ekvacioj,  Vol. 42, No. 3, 1999,  339–353. Link

• M. Henrard and  F. Sadyrbaev. Multiplicity results for fourth-order two-point boundary value problems with asymmetric  nonlinearities. Nonlinear  Analysis: TMA, Vol. 33, No. 3, 1998, 281–302. Elsevier

• F. Sadyrbaev. Multiplicity of solutions for two-point boundary value problems with asymptotically asymmetric nonlinearities, Nonlinear Analysis: TMA, Vol. 27, No. 9, 1996, 999-1012. Elsevier

• F. Sadyrbaev. Nonlinear two-point fourth order  boundary value problems.  Rocky Mountain Journal of Mathematics, Vol. 25, No. 2, 1995, 757–781. Link

Recent Conferences and Invited Talks

• F. Sadyrbaev. Oscillations in dynamical models of genetic networks (Plenary lecture, Online). The International Conference: Dynamical Systems, Modeling, and Mathematical Sciences. Dubai/UAE, September 23-25, 2022. https://dynamicalsystemsandmodeling.wordpress.com/

• F. Sadyrbaev. Creating periodic attractors for dynamical systems modelling genetic networks. International Conference „Computational and Mathematical Methods in Science and Engineering,” Costa Ballena, Cádiz, Spain, July 3 – 8, 2022.

• F. Sadyrbaev. "From Duffing equation to bio-oscillations". The International Conference „Conference on Mathematical Analysis and Applications in Science and Engineering” ISEP - Instituto Superior de Engenharia do Porto (ipp.pt), Porto, Portugal, June 27-29, 2022.

• F. Sadyrbaev, S. Atslega and E. Brokan. On controllability of gene regulatory networks. 9th Internat. Congress Industr. Appl. Mathematics (ICIAM), Valencia, Spain, July 15-19, 2019.

• F. Sadyrbaev, S. Atslega and E. Brokan. Dynamical models of interrelation in a class of artificial networks (Invited lecture). International Conference on Differential & Difference Equations and Applications 2019, (ICDDEA), Lisbon, Portugal, July 1-5, 2019.

• F. Sadyrbaev, S. Atslega and E. Brokan. Attraction in gene regulatory systems. Short communication, Intern. Congress Mathematicians 2018 (ICM 2018), Rio de Janeiro, 1–9 August 2018.

• F. Sadyrbaev, S. Atslega and E. Brokan. Modelling artificial networks. ICM2018 Satellite event International Conference on Industrial Mathematics - ICIM-2018, Foz do Iguasu, Brasil, 23–27 July 2018.

• F. Sadyrbaev, E. Brokan. On solutions of a system of ordinary differential equations arising in applications. 12th American Inst. Math. Studies Conference on Dynamical Systems (AIMS), Differential Equations and Applications, Taipei, Taiwan, July 5 - July 9, 2018.

• International conference of numerical analysis and applied mathematics (ICNAAM2016), Rhodes, Greece, 2016.   http://icnaam.org/

• 7th European Congress of Mathematics, Berlin, Germany, 2016 http://www.7ecm.de/

• International Conference on Differential and  Difference Equations & Applications, Amadora, Portugal, 2015.  https://sites.google.com/site/sandrapinelas/icddea-2015

• The 2015 International Conference on Simulation, Modelling and Mathematical Statistics, Chiang Mai, Thailand.  http://www.smms2015.org/

• Equadiff 2015, Lyon, France, 2015. https://equadiff2015.sciencesconf.org/

• F. Sadyrbaev and N. Sveikate. Quasilinearization and resonant boundary value problems. Abstracts of Equadiff 2015, Lyon, France, July 6-10, 2015. https://equadiff2015.sciencesconf.org/

• The international conference "Actual problems of mathematics and mathematical modeling", dedicated to the 50th anniversary of the foundation of the Institute of Mathematics and Mathematical Modeling of Education and Science Ministry of the Republic of Kazakhstan,  in Almaty, 2015. http://www.math.kz/conf/index.php/en/

• International Congress of Mathematicians, Seoul, Korea, 2014. http://www.icm2014.org/

• 10th AIMS International Conference on Dynamical Systems, Differential Equations and Applications, Madrid, Spain. https://www.aimsciences.org/conferences/2014/

• Bogolyubov readings DIF-2013, Differential equations,  theory of functions and their applications,  Sevastopol, Ukraine, 2013. http://www.mathnet.ru/php/conference.phtml?confid=414&option_lang=eng

• Symposium on Differential Equations and Difference Equations, Homburg/Saar, Germany, 2014.

• Conference on Differential and Difference Equations and Applications, Jasná, Slovak Republic, 2014.   http://fpv.uniza.sk/cddea2014/

• F. Sadyrbaev, A. Gritsans. On extension of Nehari-Moore example//Book of abstracts of Conference on Differential and Difference Equations and Applications, Jasná, Slovak Republic, June 23-27, 2014, P. 49. http://fpv.uniza.sk/cddea2014/

• Symposium on Differential Equations and Difference Equations SDEDE 2013, Bayrischzell, Germany, 2013.

• 18th International conference "Mathematical Modelling and Analysis" and 4th International conference "Approximation Methods and Orthogonal Expansions", Tartu, Estonia, 2013. http://www.ut.ee/mma-amoe2013/nmd3/abstraktid09876/Gritsans.pdf

• International Conference on the Theory, Methods and Applications of Nonlinear Equations, Kingsville, USA, 2012. Link

• Symposium on differential equations and difference equations, Novacella, Italy, 2012. Link

• The Fifth International Workshop Constructive methods for non-linear boundary value problems, Tokaj, Hungary, 2012. Link

• 7th European Conference on Elliptic and Parabolic Problems, Gaeta, Italy, 2012. Link

• Equadiff, Loughborough University, GB, 2011. Link

• International Conference on Differential & Difference Equations,Ponta Delgada, Portugal, 2011. Link

• General Assembly of International Mathematical Union, Bangalore, India, 2010. Link

• The 8th AIMS Conference on Dynamical Systems, Differential Equations and Applications, Dresden, Germany, 2010. Link

• Emerging Problems in Nonlinear Analysis and Differential Equations: Advances in Theory and Applications, Glasgow, 2010. Link

• Conference on Differential and Difference Equations and Applications 2010 (CDDEA 2010), Rajecke Teplice, Slovakia (invited lecturer and member of program committee). Link

• 7th ISAAC Congress, Imperial College, London, 2009. Link

• World Congress of Nonlinear Analysts 2008, FL, USA, July 2008, Orlando, FL, USA (invited lecturer in two special sessions). Link

• Conference on Boundary Value Problems Mathematical Models In Engineering, Biology And Medicine, September 16-19, 2008, Santiago de Compostela, Spain (invited lecturer). Link

• Conference on Differential and Difference Equations and Applications, Strečno, Slovak Republik, 2008 (invited lecturer and member of program committee). Link

• The 6th International Conference On Differential Equations and Dynamical Systems, May 22-26, 2008, Baltimore, Maryland, USA. Link

• Amer. Inst. Math. Stud.  7th International Conference on Dyn. Systems, Diff. Equations and Applications, University of Texas at Arlington, Texas, USA May 18 - 21, 2008. Link

• Equadiff-07, Vienna, Austria, 2007. Link

• Amer. Inst. Math. Stud. 6th International Conference on Dyn. Systems, Diff. Equations and Applications, University of Poitiers, Poitiers, France, June 25 - 28, 2006. Link

• The World Congress of Nonlinear Analysts 2004, FL, USA, July 2004, Orlando, FL, USA  (invited lecturer in two special sessions). Link

• Equadiff-2003, July 22-26, 2003,  Hasselt, Belgium. Link

• International Congress of Mathematicians, Bejing, China, 2002. Link

• Fourth International Conference on Dynamical Systems and Differential Equations,  May 24 - 27, 2002, Wilmington, NC, USA  (invited lecture).

• Member of the Latvian Mathematical Society
• Member of the American Mathematical Society