Abstract
The study of the existence of solutions of equilibrium problems on unbounded domains involves usually the same sufficient assumptions as for bounded domains together with a coercivity condition. We focus on two different conditions: the first is obtained assuming the existence of a bounded set such that no elements outside is a candidate for a solution; the second allows the solution set to be unbounded. Our results exploit the generalized monotonicity properties of the function f defining the equilibrium problem. It turns out that, in both the pseudomonotone and the quasimonotone setting, an equivalence can be stated between the nonemptyness and boundedness of the solution set and these coercivity conditions. In the pseudomonotone case, we compare our coercivity conditions with various coercivity conditions that appeared in the literature.
Similar content being viewed by others
References
T. Harker J.S. Pang (1990) ArticleTitleFinite-Dimensional Variational Inequality and Nonlinear Complementarity Problems: A Survery of Theory, Algorithms, and Applications Mathematical Programming 48 161–220
R.W. Cottle J.C. Yao (1992) ArticleTitlePseudomonotone Complementarity Problems in Hilbert Space Journal of Optimization Theory and Applications 75 281–295
A. Daniilidis N. Hadjisavvas (1999) ArticleTitleCoercivity Conditions and Variational Inequalities Mathematical Programming 86 433–438
J.P. Crouzeix (1997) ArticleTitlePseudomonotone Variational Inequality Problems: Existence of Solutions Mathematical Programming 78 305–314
M. Bianchi N. Hadjisavvas S. Schaible (2004) ArticleTitleMinimal Coercivity Conditions for Variational Inequalities–Application to Exceptional Families of Elements Journal of Optimization Theory and Applications 122 1–17
D. Aussel N. Hadjisavvas (2004) ArticleTitleOn Quasimonotone Variational Inequalities Journal of Optimization Theory and Applications 121 445–450
F. Flores-bazán (2000) ArticleTitleExistence Theorems for Generalized Noncoercive Equilibrium Problems: The Quasiconvex Case SIAM Journal on Optimization 11 675–690
N. Hadjisavvas (2003) ArticleTitleContinuity and Maximality Properties of Pseudomonotone Operators Journal of Convex Analysis 10 465–475
S. Karamardian (1971) ArticleTitleGeneralized Complementarity Problem Journal of Optimization Theory and Applications 8 161–168
M. Bianchi R. Pini (2001) ArticleTitleA Note on Equilibrium Problems for Properly Quasimonotone Bifunctions Journal of Global Optimization 20 67–76
M. Bianchi S. Schaible (1996) ArticleTitleGeneralized Monotone Bifunctions and Equilibrium Problems Journal of Optimization Theory and Applications 90 31–43
Y.B. Zhao J.Y. Han H.D. Qi (1999) ArticleTitleExceptional Families and Existence Theorems for Variational Inequalities Problems Journal of Optimization Theory and Applications 101 475–495
H. Brezis L. Nirenberg G. Stampacchia (1972) ArticleTitleA Remark on Fan’s Minimax Principle Bollettino dell’Unione Matematica Italiana 6 293–300
Author information
Authors and Affiliations
Additional information
We thank an anonymous referee for valuable comments and suggestions.
Rights and permissions
About this article
Cite this article
Bianchi, M., Pini, R. Coercivity Conditions for Equilibrium Problems. J Optim Theory Appl 124, 79–92 (2005). https://doi.org/10.1007/s10957-004-6466-9
Issue Date:
DOI: https://doi.org/10.1007/s10957-004-6466-9