FINITE-DIFFERENCE STOCHASTIC SCHEMES FOR MINIMIZING A STRONGLY QUASICONVEX NON-DIFFERENTIABLE FUNCTION ON ℝn. THE NURMINSKII METHOD

Authors

  • Rafik A. Khachatryan Chair of Numerical Analysis and Mathematical Modelling, YSU, Armenia
  • Zohrab B. Hovhannisyan Chair of Numerical Analysis and Mathematical Modelling, YSU, Armenia https://orcid.org/0009-0005-5873-5231

DOI:

https://doi.org/10.46991/PYSUA.2026.60.1.023

Keywords:

optimization, quasi convex function, subgradient, finite-difference scheme, convergence rate

Abstract

In this work, stochastic approximation methods based on finite-differences are investigated for the problem of minimizing quasiconvex functions. The main result of this work is the derivation of convergence rate estimates for stochastic finite-difference methods in the case of quasiconvex functions. The obtained results significantly extend the applicability of stochastic finite-difference methods to nonsmooth quasiconvex optimization problems and provide a rigorous justification for their use in black-box settings where the oracle returns only function values.

Downloads

Download data is not yet available.

References

Lara F. On Strongly Quasiconvex Functions: Existence Results and Proximal Point Algorithm. JOTA 192 (2022), 891-911. https://doi.org/10.1007/s10957-021-01996-8

Lara F., Marcavillaca R.T., Yuong P.T. Characterizations, Dynamical Systems and Gradient Methods for Strongly Quasiconvex Functions. (2024). https://doi.org/10.48550/arXiv.2410.03534

Mikhalevich V.S., Gupal A.M., Norkin V.I. Methods of Nonconvex Optimization. Moscow, Nauka (1983).

Nesterov Yu.E. Minimization Methods for Non-smooth Convex and Quasiconvex Functions. Matekon 29 (1984), 519-531.

Shamir O., Zhang T. Stochastic Gradient Descent for Non-smooth Optimization. (2012). https://doi.org/10.48550/arXiv.1212.1824

Gupal A.M. Algorithms for Finding the Extremum of Nondifferentiable Functions with Constraint. Kyiv, Institute of Cybernetics, Preprint (1976).

Nesterov Yu.E., Spokoiny V. Random Gradient-Free Minimization of Convex Functions. Foundations of Computational Mathematics 17 (2017), 527-566. https://doi.org/10.1007/s10208-015-9296-2

Polyak B.T. Existence Theorems and Convergence of Minimizing Sequences in Extremum Problems with Restrictions. Soviet Math. Dokl. 7 (1966), 72-75.

Jovanovic M.V. A Note on Strongly Convex and Quasiconvex Functions. Math. Notes 60 (1996), 584-585. https://doi.org/10.1007/BF02309176

Jovanovic M.V. Strongly Quasiconvex Quadratic Functions. Publications de l'institut Mathematique Nouvelle Serie 53 (1993), 153-156.

Hazan E. Introduction to Online Convex Optimization. Essential Knowledge, Boston-Delt (2016).

Grad S.M., Lara F., Marcavillaca R.T. Strongly Quasiconvex Functions, What We Know (So Far). (2024). https://doi.org/10.48550/arXiv.2410.23055

Nurminskii E.A. Numerical Methods for Solving Deterministic and Stochastic Minimax Problems. Kiev, Naukova Dumka (1979).

Robbins H., Siegmund D. A Convergence Rate Theorem for Non Negative Almost Supermartingales and Some Applications. Optimizing Methods in Statistics 8 (1971), 233-257. https://doi.org/10.1016/B978-0-12-604550-5.50015-8

Downloads

Published

2026-04-14

Issue

Section

Mathematics

How to Cite

Khachatryan, R. A., & Hovhannisyan, Z. B. (2026). FINITE-DIFFERENCE STOCHASTIC SCHEMES FOR MINIMIZING A STRONGLY QUASICONVEX NON-DIFFERENTIABLE FUNCTION ON ℝn. THE NURMINSKII METHOD. Proceedings of the YSU A: Physical and Mathematical Sciences, 60(1 (269), 23-33. https://doi.org/10.46991/PYSUA.2026.60.1.023