Stochastic Differential Inclusions and Tikhonov Regularization for Stochastic Non-Smooth Convex Optimization in Hilbert spaces
Open Journal of Mathematical Optimization, Volume 6 (2025), article no. 9, 30 p.

To solve convex optimization problems with a noisy gradient input, we analyze the global behavior of subgradient-like flows under stochastic errors. The objective function is composite, being equal to the sum of two convex functions, one being differentiable and the other potentially non-smooth. We then use stochastic differential inclusions where the drift term is minus the subgradient of the objective function, and the diffusion term is either bounded or square-integrable. In this context, under Lipschitz’s continuity of the differentiable term and a growth condition of the non-smooth term, our first main result shows almost sure weak convergence of the trajectory process towards a minimizer of the objective function. Then, using Tikhonov regularization with a properly tuned vanishing parameter, we can obtain almost sure strong convergence of the trajectory towards the minimum norm solution. We find an explicit tuning of this parameter when our objective function satisfies a local error-bound inequality. We also provide a comprehensive complexity analysis by establishing several new pointwise and ergodic convergence rates in expectation for the convex, strongly convex, and Łojasiewicz case.

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DOI: 10.5802/ojmo.44
Keywords: Stochastic optimization, inertial gradient system, Convex optimization, Non-smooth optimization, Stochastic Differential Equation, Stochastic Differential Inclusion, Tikhonov regularization, Error bound inequality, Łojasiewicz inequality, KL inequality, Convergence rate, Asymptotic behavior.

Rodrigo Maulen-Soto 1; Jalal Fadili 1; Hedy Attouch 2

1 Normandie Université, ENSICAEN, UNICAEN, CNRS, GREYC 6 Bd. Marechal Juin, Caen, France
2 IMAG, CNRS, Université Montpellier 499-554 Rue du Truel 9, Montpellier, France
License: CC-BY 4.0
Copyrights: The authors retain unrestricted copyrights and publishing rights
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Rodrigo Maulen-Soto; Jalal Fadili; Hedy Attouch. Stochastic Differential Inclusions and Tikhonov Regularization for Stochastic Non-Smooth Convex Optimization in Hilbert spaces. Open Journal of Mathematical Optimization, Volume 6 (2025), article  no. 9, 30 p.. doi: 10.5802/ojmo.44

[1] M. Akgül Topics in Relaxation and Ellipsoidal Methods, Research Notes in Mathematics, 97, Pitman Publishing, 1984 | Zbl | MR

[2] Hedy Attouch; Zaki Chbani; Hassan Riahi Accelerated gradient methods with strong convergence to the minimum norm minimizer: a dynamic approach combining time scaling, averaging, and Tikhonov regularization (2022) | arXiv

[3] Hedy Attouch; Roberto Cominetti A Dynamical Approach to Convex Minimization Coupling Approximation with the Steepest Descent Method, J. Differ. Equations, Volume 128 (1996) no. 2, pp. 519-540 | DOI | Zbl | MR

[4] Hedy Attouch; Marc-Olivier Czarnecki Asymptotic behavior of coupled dynamical systems with multiscale aspects, J. Differ. Equations, Volume 248 (2010) no. 6, pp. 1315-1344 | DOI | Zbl | MR

[5] Hedy Attouch; Jalal Fadili; Vyacheslav Kungurtsev On the effect of perturbations in first-order optimization methods with inertia and Hessian driven damping, Evol. Equ. Control Theory, Volume 12 (2023) no. 1, pp. 71-117 | DOI | Zbl | MR

[6] Hedy Attouch; Abdellatif Moudafi; Hassan Riahi Quantitative stability analysis for maximal monotone operators and semi-groups of contractions, Nonlinear Anal., Theory Methods Appl., Volume 21 (1993) no. 9, pp. 697-723 | DOI | Zbl | MR

[7] Hedy Attouch; Roger J.-B. Wets Quantitative stability of variational systems: I, The epigraphical distance, Trans. Am. Math. Soc., Volume 328 (1991) no. 2, pp. 695-729 | Zbl | MR

[8] Jean-Pierre Aubin; Giuseppe Da Prato The viability theorem for stochastic differential inclusions, Stochastic Anal. Appl., Volume 16 (1998), pp. 1-15 | DOI | Zbl | MR

[9] Heinz Bauschke; Patrick L. Combettes Convex Analysis and Monotone Operator Theory in Hilbert Spaces, Springer, 2017 | DOI | Zbl | MR

[10] Gheorghe Bocşan On Wiener stochastic integrals of multifunctions, Seminarul de Teoria Probabilitatilor si Applicatii, Univ. Timisoara, 1987, pp. 1-7

[11] Jerome Bolte; Trong Phong Nguyen; Juan Peypouquet; Bruce W. Suter From error bounds to the complexity of first-order descent methods for convex functions, Mathematical Programming (Jon Lee; Sven Leyffer, eds.) (Mathematical Optimization Society), Volume 165, Springer, 2016, pp. 471-507 | DOI | Zbl | MR

[12] Haïm Brézis Operateurs maximaux monotones et semi-groupes de contractions dans les espace Hilbert, North-Holland Mathematics Studies, 5, American Elsevier Publishing Comp., 1973 | Zbl | MR

[13] Felix E. Browder Existence and approximation of solutions of nonlinear variational inequalities, Proc. Natl. Acad. Sci. USA, Volume 56 (1966), pp. 1080-1086 | DOI | Zbl | MR

[14] Felix E. Browder Convergence of approximants to fixed points of nonexpansive nonlinear mappings in Banach spaces, Arch. Ration. Mech. Anal., Volume 24 (1967), pp. 82-90 | DOI | Zbl | MR

[15] Donald L. Burkholder; Brian Davis; Richard F. Gundy Integral inequalities for convex functions of operators on martingales, Proc. 6th Berkeley Symp. Math. Statistics and Probability, 1972, pp. 223-240 | Zbl

[16] Augustin Cauchy Méthode générale pour la résolution des systèmes d’équations simultanées, C. R. Acad. Sci. Paris, Volume 25 (1847), pp. 536-538

[17] Emmanuel Cépa Équations différentielles stochastiques multivoques, Séminaire de probabilités XXIX (Strasbourg) (Lecture Notes in Mathematics), Volume 1613, Springer, 1995, pp. 86-107 | DOI | Numdam | Zbl

[18] Roberto Cominetti; Juan Peypouquet; Sylvain Sorin Strong asymptotic convergence of evolution equations governed by maximal monotone operators with Tikhonov regularization, J. Differ. Equations, Volume 245 (2008), pp. 3753-3763 | DOI | Zbl | MR

[19] Giuseppe Da Prato; Jerzy Zabszyk Stochastic equations in infinite dimensions, Encyclopedia of Mathematics and Its Applications, 44, Cambridge University Press, 1992 | DOI | Zbl | MR

[20] Leszek Gawarecki; Vidyadhar Mandrekar Stochastic Differential Equations in Infinite Dimensions, Probability and Its Applications, Springer, 2011 | DOI | Zbl

[21] Joe Ghafari A proof and an application of the continuous parameter martingale convergence theorem, Res. Stat., Volume 1 (2023) no. 1 | DOI

[22] T. E. Govindan Yosida Approximations of Stochastic Differential Equations in Infinite Dimensions and Applications, Probability Theory and Stochastic Modelling, 79, Springer, 2016 | MR | DOI | Zbl

[23] Joachim Gwinner Bibliography on non-differentiable optimization and non-smooth analysis, J. Comput. Appl. Math., Volume 7 (1981), pp. 277-285 | MR | DOI | Zbl

[24] Desmond J. Higham; Xuerong Mao; Andrew M. Stuart Strong convergence of Euler-type methods for nonlinear stochastic differential equations, SIAM J. Numer. Anal., Volume 40 (2006) no. 3, pp. 1041-1063 | MR | DOI | Zbl

[25] Michał Kisielewicz Stochastic differential inclusions and applications, Springer Optimization and Its Applications, 80, Springer, 2013 | DOI | MR | Zbl

[26] Krzysztof C. Kiwiel; Torbjörn Larsson; Per O. Lindberg Lagrangian relaxation via ballstep subgradient methods, Math. Oper. Res., Volume 32 (2007) no. 3, pp. 669-686 | DOI | MR | Zbl

[27] Paul Krée Diffusion equation for multivalued stochastic differential equations, J. Funct. Anal., Volume 49 (1982) no. 1, pp. 73-90 | MR | Zbl | DOI

[28] Claude Lemaréchal Lagrangian relaxation, Computational combinatorial optimization. Optimal of probably near-optimal solutions (Lecture Notes in Computer Science), Volume 2241, 2001, pp. 112-156 | DOI | Zbl

[29] Xuerong Mao Stochastic differential equations and applications, Horwood Publishing, 2007 | Zbl | MR

[30] Rodrigo Maulen-Soto; Jalal Fadili; Hedy Attouch An Stochastic Differential Equation Perspective on Stochastic Convex Optimization, Math. Oper. Res. (2024) (Ahead of Print) | DOI

[31] NIST Handbook of Mathematical Functions (Frank W. J. Olver; Daniel w. Lozier; Ronald F. Boisvert; Charles W. Clarck, eds.), Cambridge University Press, 2010 | MR | Zbl

[32] Zdzisław Opial Weak convergence of the sequence of successive approximations for nonexpansive mappings, Bull. Am. Math. Soc., Volume 73 (1967), pp. 591-597 | DOI | MR

[33] Etienne Pardoux; Aurel Răşcanu Stochastic differential equations, backward SDEs, partial differential equations, Stochastic Modelling and Applied Probability, 69, Springer, 2014 | DOI | Zbl | MR

[34] Roger Pettersson Yosida approximations for multivalued stochastic differential equations, Stochastics Stochastics Rep., Volume 52 (1994), pp. 107-120 | DOI | Zbl | MR

[35] Aurel Rascanu Deterministic and Stochastic Differential Equations in Hilbert spaces involving Multivalued Maximal Monotone Operators (2014) | arXiv

[36] Aurel Rascanu; Eduard Rotenstein The Fitzpatrick function – a bridge betweem convex analysis and multivalued stochastic differential equations (2009) | arXiv

[37] Herbert Robins; Sutton Monro A stochastic approximation method, Ann. Math. Stat., Volume 22 (1951), pp. 400-407 | DOI | Zbl | MR

[38] R. Tyrrell Rockafellar Convex analysis, Princeton Landmarks in Mathematics, 28, Princeton University Press, 1997 | Zbl | MR

[39] Walter Rudin Real and complex analysis, McGraw-Hill, 1987 | Zbl | MR

[40] Frank S. Scalora Abstract martingale convergence theorems, Pac. J. Math., Volume 11 (1961) no. 1, pp. 347-374 | DOI | MR | Zbl

[41] Naum Z. Shor Minimization Methods for non-differentiable functions, Springer Series in Computational Mathematics, 3, Springer, 1985 | DOI | Zbl | MR

[42] Rodrigo Maulen Soto A Dynamical System Perspective on Stochastic and Inertial Methods for Optimization, Ph. D. Thesis, Université de Caen Normandie (France) (2024)

[43] Jaewook J. Suh; Jisun Park; Ernest K. Ryu Continuous-time Analysis of Anchor Acceleration, NIPS ’23: Proceedings of the 37th International Conference on Neural Information Processing Systems, Curran Associates, Inc. (2023), pp. 32782-32866

[44] Denis Torralba Convergence epigraphique et changements d’echelle en analyse variationelle et optimisation, Ph. D. Thesis, Université de Montpellier 2 (France) (1996), 160 pages

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