Abstract
A local minimum of a quasiconvex function is not necessarily a global minimum. In this paper, we show that every lower semicontinuous quasiconvex function can be approximated uniformly by a sequence of quasiconvex functions for which every local minimum is a global minimum. We also study the continuity of the functions appearing in a recently obtained decomposition of quasiconvex functions.
Similar content being viewed by others
References
Al-Homidan, S., Hadjisavvas, N., Shaalan, L.: Transformation of quasiconvex functions to eliminate local minima. J. Optim. Theory Appl. 177, 93–105 (2018)
Aussel, D., Eberhard, A.: Maximal quasimonotonicity and dense single-directional properties of quasimonotone operators. Math. Program. Ser. B 139, 27–54 (2013)
Aussel, D., Hadjisavvas, N.: Adjusted sublevel sets, normal operator and quasiconvex programming. SIAM J. Optim. 16, 358–367 (2005)
Aussel, D., Sagratella, S.: Sufficient conditions to compute any solution of a quasivariational inequality via a variational inequality. Math. Methods Oper. Res. 85, 3–18 (2017)
Avriel, M., Diewert, W.E., Schaible, S., Zang, I.: Generalized Concavity, Classics in Applied Mathematics. SIAM, Philadelphia (2010)
Cambini, A., Martein, L.: Generalized Convexity and Optimization, Theory and Applications. Springer, Berlin (2009)
Connell, C., Rasmusen, E.: Concavifying the quasi-concave. J. Convex Anal. 24, 1239–1262 (2017)
Da Cruz Neto, J.X., Lopes, J.O., Travaglia, M.V.: Algorithms for quasiconvex minimization. Optimization 60, 1105–1117 (2011)
Hadjisavvas, N., Lara, F., Martínez-Legaz, J.E.: A quasiconvex asymptotic function with applications in optimization. J. Optim. Theory Appl. 180, 170–186 (2019)
Lucchetti, R., Milasi, M.: Semistrictly quasiconcave approximation and an application to general equilibrium theory. J. Math. Anal. Appl. 428, 445–456 (2015)
Lucchetti, R., Milasi, M.: Approximating quasiconvex functions with strictly quasiconvex ones in Banach space. Set-Valued Var. Anal. 25, 591–602 (2017)
Martos, B.: Subdefinite matrices and quadratic forms. SIAM J. Appl. Math. 17, 1215–1223 (1969)
Penot, J.P.: What is quasiconvex analysis? Optimization 47, 35–110 (2000)
Schaible, S., Ziemba, W.T.: Generalized Concavity in Optimization and Economics. Academic Press, New York (1981)
Shaalan, L.: Transformations of quasiconvex functions by scaling: construction, properties and uses. Ph.D. Thesis, King Fahd University of Petroleum and Minerals, Saudi Arabia (2018)
Thach, P.T., Kojima, M.: A generalized convexity and a homotopy approach to a quasiconvex minimization (nonlinear analysis and mathematical economics). Proc. Inst. Math. Anal. 861, 77–94 (1994)
Acknowledgements
The authors are grateful to KFUPM, Dhahran, Saudi Arabia for providing excellent research facilities. They would also like to thank the referee for his/her useful comments and suggestions that helped to improve the paper.
Author information
Authors and Affiliations
Corresponding author
Additional information
Dedicated to Nicolas Hadjisavvas on the occasion of his 65th birthday.
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
Al-Homidan, S., Shaalan, L. Approximation of quasiconvex functions by neatly quasiconvex functions. Optim Lett 15, 979–989 (2021). https://doi.org/10.1007/s11590-020-01535-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11590-020-01535-w