Abstract
We present two projection extragradient algorithms for solving equilibrium problems without monotonicity and Lipschitz-type property in Hilbert spaces. Our strategy consists in embedding a subgradient projection step in the extragradient algorithm and employing an Armijo-linesearch. The strategy guarantees that the sequences generated by the presented algorithms converge weakly and strongly to a solution of the equilibrium problem, respectively. The convergence does not require any monotonicity and Lipschitz-type property of the bifunction but the nonemptyness of the solution set of the associated Minty equilibrium problem. Some numerical experiments illustrate the efficiency of the proposed algorithms.
Similar content being viewed by others
References
Blum, E., Oettli, W.: From optimization and variational inequalities to equilibrium problems. Math. Student. 63, 127–149 (1994)
Fan, K.: A minimax inequality and applications. In: Shisha, O (ed.) Inequality III, pp 103–113. Academic Press, New York (1972)
Iusem, A.N., Sosa, W.: New existence results for equilibrium problems. Nonlinear Anal. TMA 52, 621–635 (2003)
Bigi, G., Pappalardo, M., Passacantando, M.: Existence and solution methods for equilibria. Eur. J. Oper. Res. 227(1), 1–11 (2013)
Tran, D.Q., Dung, M.L., Nguyen, V.H.: Extragradient algorithms extended to equilibrium problems. Optimization 57(6), 749–776 (2008)
Strodiot, J.J., Nguyen, T.T.V., Nguyen, V.H.: A new class of hybrid extragradient algorithms for solving quasi-equilibrium problems. J. Glob. Optim. 56, 373–397 (2013)
Muu, L.D., Quoc, T.D.: Regularization algorithms for solving monotone Ky Fan inequalities with application to a Nash-Cournot equilibrium model. J. Optim. Theory Appl. 142, 185–204 (2009)
Lions, J.L., Stampacchia, G.: Variational inequalities. Comm. Pure Appl. Math. 20(3), 493–519 (1967)
Mastroeni, G.: On auxiliary principle for equilibrium problems. In: Daniele, P., Giannessi, F., Maugeri, A (eds.) Equilibrium Problems and Variational Models, pp 289–298. Kluwer Academic Publishers, Dordrecht (2003)
Flam, S.D., Antipin, A.S.: Equilibrium programming using proximal-like algorithms. Math. Program. 78, 29–41 (1997)
Korpelevich, G.M.: The extragradient method for finding saddle points and other problems. Matekon. 12(4), 747–756 (1976)
Dinh, B.V., Kim, D.S.: Projection algorithms for solving nonmonotone equilibrium problems in Hilbert space. J. Comput. Appl. Math. 302, 106–117 (2016)
Ye, M., He, Y.: A double projection method for solving variational inequalities without monotonicity. Comput. Optim. Appl. 60, 141–150 (2015)
Nguyen, T.T.V., Strodiot, J.J., Nguyen, V.H.: The interior proximal extragradient method for solving equilibrium problems. J. Glob. Optim. 44, 175–192 (2009)
Strodiot, J.J., Vuong, P.T., Nguyen, T.T.V.: A class of shrinking projection extragradient methods for solving non-monotone equilibrium problems in Hilbert spaces. J. Glob. Optim. 64, 159–178 (2016)
Quoc, T.D., Anh, P.N., Muu, L.D.: Dual extragradient algorithms extended to equilibrium problems. J. Glob. Optim. 52, 139–159 (2012)
Iyiola, O.S., Ogbuisi, F.U., Shehu, Y.: An inertial type iterative method with Armijo linesearch for nonomonotone equilibrium problems. Calcolo. 55(4), 1–22 (2018)
Dinh, B.V., Muu, L.D.: A projection algorithm for solving pseudomonotone equilibrium problems and it’s application to a class of bilevel equilibria. Optimization 64, 559–575 (2015)
Vuong, P.T., Strodiot, J.J., Nguyen, V.H.: Extragradient methods and linesearch algorithms for solving Ky Fan inequalities and fixed point problems. J. Optim. Theory Appl. 155, 605–627 (2012)
Nguyen, T.T.V., Strodiot, J.J., Nguyen, V.H.: Hybrid methods for solving simultaneously an equilibrium problem and countably many fixed point problems in a Hilbert space. J. Optim. Theory Appl. 160, 809–831 (2014)
Anh, P.N., An, L.T.H.: The subgradient extragradient method extended to equilibrium problems. Optimization 64(2), 225–248 (2015)
Solodov, M.V., Svaiter, B.F.: A new projection method for variational inequality. SIAM J. Control Optim. 37, 765–776 (1999)
Iusem, A.N., Svaiter, B.F.: A variant of Korpelevich’s method for variational inequalities with a new search strategy. Optimization 42, 309–321 (1997)
Takahashi, W., Takeuchi, Y., Kubota, R.: Strong convergence theorems by hybrid methods for families of nonexpansive mappings in Hilbert spaces. J. Math. Anal. Appl. 341, 276–286 (2008)
Censor, Y., Gibali, A., Reich, S.: Strong convergence of subgradient extragradient methods for variational inequality problem in Hilbert space. Optim. Methods Softw. 26, 827–845 (2011)
Nakajo, K., Shimoji, K., Takahashi, W.: Strong convergence to common fixed points of families of nonexpansive mappings in Banach spaces. J. Nonlinear Convex Anal. 8, 11–34 (2007)
Konnov, I.V., Dyabilkin, D.A.: Non-monotone equilibrium problems: Coercivity conditions and weak regularization. J. Glob. Optim. 49, 575–587 (2011)
Konnov, I.V.: Application of the proximal point method to nonmonotone equilibrium problems. J. Optim. Theory Appl. 119(2), 317–333 (2003)
Bauschke, H.H., Combettes, P.L.: Convex Analysis and Monotone Operator Theory in Hilbert Spaces. Springer, New York (2011)
Bigi, G., Passacantando, M.: Auxiliary problem principles for equilibria. Optimization 66(12), 1955–1972 (2017)
Opial, Z.: Weak convergence of the sequence of successive approximations for nonexpansive mappings. Bull. Am. Math. Soc. 73, 591–597 (1967)
Yanes, C.M., Xu, H.K.: Strong convergence of the CQ method for fixed point iteration processes. Nonlinear Anal. TMA. 64, 2400–2411 (2006)
Vuong, P.T., Strodiot, J.J., Nguyen, V.H.: On extragradient-viscosity methods for solving equilibrium and fixed point problems in a Hilbert space. Optimization 64 (2), 429–451 (2015)
Acknowledgments
The authors would like to thank the referees and the editor for their helpful comments and suggestions which have led to the improvement of the early version of this paper.
Funding
This work was partially supported by the National Science Foundation of China (11471230 and 11771067) and the Scientific Research Foundation of the Education Department of Sichuan Province (16ZA0213).
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Deng, L., Hu, R. & Fang, Y. Projection extragradient algorithms for solving nonmonotone and non-Lipschitzian equilibrium problems in Hilbert spaces. Numer Algor 86, 191–221 (2021). https://doi.org/10.1007/s11075-020-00885-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11075-020-00885-x