- Research
- Open access
- Published:
A new system of generalized quasi-variational-like inclusions with noncompact valued mappings
Journal of Inequalities and Applications volume 2012, Article number: 41 (2012)
Abstract
In this article, we introduce and study a new system of generalized quasi-variational-like inclusions with noncompact valued mappings. By using the η- proximal mapping technique, we prove the existence of solutions and the convergence of some new N-step iterative algorithms for this system of generalized quasi-variational-like inclusions. Our results extend and improve some known results in the literature.
Mathematics Subject Classification 2000: 49H09; 49J40; 49H10.
1 Introduction
Let H be a real Hilbert space, and CB(H) be the family of all nonempty bounded closed subsets of H. We will consider the following problem:
For i, j = 1, 2, . . . , N, let A ij : H → CB(H), η i : H × H → H, g i : H → H, be nonlinear mappings, and let φ i : H → R ∪ {+∞} be real function.
Find, such that
Problem (1.1) is called the set-valued nonlinear generalized quasi-variational-like inclusions.
Various special cases of the problem (1.1) had been studied by many authors before. Here, we mention some of them as follows:
-
(1)
If N = 2, A 11 = A 12 = A, A 21 = A 22 = B, T 1 = T, T 1(A(·), B(·)) : H → CB(H), then the problem (1.1) reduces to find x* ∈ H, u* ∈ Ax*, v* ∈ Bx* such that
(1.2)
Problem (1.2) was introduced and studied by Ding [1] in 2001.
-
(2)
If N = 2, A 11 = A 12 = A 21 = A 22 = I, g i = I (identical operator), η(x, y) = x-y, φ 1 = φ 2 = φ, T : H × H → H, T 1(A 11 x, A 12 y) = ρ 1 T (A 12 y, A 11 x) + A 11 x - A 12 y, T 2(A 21 x, A 22 y) = ρ 2 T (A 21 x, A 22 y) + A 22 y - A 21 x, then the problem (1.1) reduces to find x*, y* ∈ H such that
(1.3)
Problem (1.3) was studied by He and Gu [2] in 2009.
-
(3)
Let K ⊂ H be a closed convex subset, φ(x) = I K (x), the problem (1.3) reduces to find x*, y* ∈ K such that
(1.4)
Problem (1.4) was inspected and studied by Chang [3], Verma [4, 5] and Huang [6].
-
(4)
If N = 2, A 11 = A 12 = A 21 = A 22 = I, g : H → H, T 1(x, y) = ρ 1 Ty + g(x) - g(y), T 2(x, y) = ρ 2 Tx + g(y) - g(x), (ρ 1, ρ 2 > 0), η(x, y) = g(x) - g(y), then the problem (1.1) reduces to find x*, y* ∈ H such that
(1.5)
Problem (1.5) was introduced and studied by Hajjafar and Verma [7].
-
(5)
If N = 3, η(x, y) = x - y, then the problem (1.1) reduces to find such that
(1.6)
Problem (1.6) was studied by Kazmi et al. [8].
For more special cases, please refer to [1–9] and the references therein.
Remark 1.1. Yang [10] pointed out a fact for the problem (1.4) discussed in reference [5], namely, if the problem (1.4) has a solution (x*, y*), then x* = y*. Therefore, actually, the problem(1.4) is a single variational inequality:
In this article, we study the problem (1.1). By using the η proximal mapping technique, we prove the existence of solutions and approximate the solutions by some new N - step iterative algorithms. Our results extend and improve some known results in the references [1–9].
2 Preliminaries
In this article, we need the following concepts and lemmas.
Definition 2.1[1] A mapping g : H → H is said to be
-
(i)
ξ-strongly monotone if there exists a constant ξ > 0 such that
-
(ii)
ζ-Lipschitz continuous if there exists a constant ζ > 0 such that
Definition 2.2[1] A mapping η : H × H → H is said to be
-
(i)
σ - strongly monotone if there exists a constant σ > 0 such that
-
(ii)
τ - Lipschitz continuous if there exists a constant τ > 0 such that
Definition 2.3[1, 11] Let A : H → CB(H) be a set-valued mapping, is said to be
-
(i)
α - (A, g)-strongly monotone in the i th argument if α > 0 such that
-
(ii)
(s 1, s 2, . . . , s N )-Lipschitz continuous if there exist constants s 1, s 2, . . . , s N > 0 such that for all x i , y i ∈ H, i = 1, 2, . . . , N,
-
(iii)
A set-valued A is said to be δ - H - Lipschitz continuous if there exists a constant δ > 0 such that
where H(·,·) is the Hausdorff metric on CB(H).
Definition 2.4[1] A functional f : H ×H → R∪{+∞} is said to be 0-diagonally quasi-concave (in short,0-DQCV) in x, if for any finite set {x1, . . . , x N } ⊂ H and for any with λ i ≥ 0 and ,
Definition 2.5[1] Let η : H × H → H be a single-valued mapping. A proper functional φ : H → R∪{+∞} is said to be η- subdifferentiable at a point x ∈ H, if there exists a point f * ∈ H such that
where f * is called a η- subgradient of φ at x. The set of all η- subgradients of φ at x is denoted by ∂ η φ(x). We have
Definition 2.6[1] Let η, φ be according to Definition 2.5, if for each x ∈ H and ρ > 0,there exists a unique point u ∈ H such that
then the mapping denoted by , is said to be η- proximal mapping of φ. By (2.1) and the definition of , we have x - u ∈ ρ∂ η φ(x), it follows that
Lemma 2.1[1] Let η : H × H → H be continuous and σ- strongly monotone such that η(x, y) = -η(y, x) for all x, y ∈ H. And for any given x ∈ H, the function h(y, u) = 〈x - u, η(y, u)〉 is 0-DQCV in y. Let φ : H → R ∪ {+∞} be a lower semicontinuous η- subdifferentiable proper functional on H, then for any given ρ > 0 and x ∈ H there exists a unique u ∈ H such that
i.e., .
Lemma 2.2 Let η : H × H → H be σ- strongly monotone and τ - Lipschitz continuous such that η(x, y) = -η(y, x). Let h(y, u), φ, ρ be according to Lemma 2.1, then the η- proximal mapping of φ is - Lipschitz continuous.
3 Main results
Theorem 3.1 is a solution of problem (1.1) if and only if satisfies the following relation: For every i = 1, 2, . . . N,
where
Proof. Assume the satisfies relation (3.1). Since , we have
i.e.,
By the Definition 2.5 of η i - subdifferential, the above relation holds if and only if
and hence
i = 1, 2, . . . , N. i.e., is a solution of the problem (1.1). □
Now, we give iterative algorithms of problem (1.1).
Algorithm(I) For given , let
By Nadler [12], for i = 1, 2, . . . , N, j = 1, 2, . . . , N, there exists such that
Let
By induction, we can define sequences satisfying
where for any i, j = 1, 2, . . . , N; n = 0, 1, 2, . . . ,
Theorem 3.2 Let H be a real Hilbert space. For i, j = 1, 2, . . . , N, let set-valued mapping A ij : H → CB(H) be δ ij - H - Lipschitz continuous. Let mapping η i : H × H → H be σ i - strongly monotone and τ i -Lipschitz continuous such that η i (x, y) = -η i (y, x) for all x, y ∈ H and for any given x ∈ H, the function h i (y, u) = 〈x - g i (u), η i (y, u)〉 is 0-DQCU in y. Let mapping g i : H → H be ξ i - strongly monotone and ζ i - Lipschitz continuous, and be (s1, . . . , s N )- Lipschitz continuous and α i - (A ij , g i )- strongly monotone in the i th argument. Let φ i : H → R ∪ {+∞} be a lower semicontinuous η i - subdifferentiable proper functional. If there exist ρ1, . . . , ρ N > 0 such that for all i = 1, 2, . . . , N
then the iterative sequences , generated by algorithm (I) converge strongly to , respectively, and is a solution of the problem (1.1).
Proof. For i = 1, 2, . . . , N, by algorithm (I) and Lemma 2.2, we have
Since g i is ξ i - strongly monotone and ζ i - Lipschitz continuous, we obtain
Notice that,
Since T i is (s1, . . . , s N )- Lipschitz continuous and α i - (A ij , g i )- strongly monotone in the i th argument, we get
Therefore,
And
It follows from (3.3)-(3.8) that for every i = 1, 2, . . . ,N,
So,
where
Letting
from (3.2) we have 0 < θ < 1, and hence are also Cauchy sequences. Thus there exist such that i = 1, 2, . . . ,N.
Now we prove for i = 1, 2, . . . ,N, j = 1, 2, . . . ,N. By
It follows that are also Cauchy sequence. Therefore, there exist such that
Note that
We have Since is closed, , for each i = 1,2, . . . ,N, j = 1, 2, . . . ,N. By
and the continuity of let n → ∞, we have that
and
0By Theorem 3.1, is a solution of the problem (1.1). This completes the proof.□
Remark 3.1 For a suitable choice of T i , A ij , η i , g i and φ i , Theorem 3.2 includes many known results of generalized quasi-variational-like inclusions as special cases (see [1–8]),where φ i is nonconvex and A ij is noncompact.
References
Ding XP: Generalized quasi-variational-like inclusions with nonconvex functional. Appl Math Comput 2001, 122: 267–282. 10.1016/S0096-3003(00)00027-8
He Z, Gu F: Generalized system for relaxed cocoercive mixed variational inequalities in Hilbert spaces. Appl Math Comput 2009, 214: 26–30. 10.1016/j.amc.2009.03.056
Chang SS, Joseph Lee HW, Chan CK: Generalized system for relaxed cocoercive variational inequalities in Hilbert spaces. Appl Math Lett 2007, 20: 329–334. 10.1016/j.aml.2006.04.017
Verma RU: General convergence analysis for two-step projection methods and applications to variational problems. Appl Math Lett 2005, 18: 1286–1292. 10.1016/j.aml.2005.02.026
Verma RU: Projection methods, algorithms and a new system of nonlinear variational inequalities. Comput Math Appl 2001, 42: 1025–1031. 10.1016/S0898-1221(01)00218-8
Huang Z, Noor MA: An explicit projection method for a system of nonlinear variational inequalities with dierent ( γ , r )-cocoercive mapping. Appl Math Comput 2007, 190: 356–361. 10.1016/j.amc.2007.01.032
Hajjafar A, Verma RU: General approximation solvability of a system of strongly g-r-pseudomonotonic nonlinear variational inequalities and projection methods. Math Comput Model 2006, 43: 150–157. 10.1016/j.mcm.2005.01.038
Kazmi KR, Bhat MI, Naeem Ahmad: An iterative algorithm based on M -proximal mappings for a system of generalized implicit variational inclusions in Banach spaces. J Comput Appl Math 2009, 233(2):361–371. 10.1016/j.cam.2009.07.028
Ahmad R, Siddiqi AH, Khan Z: Proximal point algorithm for generalized multivalued nonlinear quasi-variational-like inclusions in Banach spaces. Appl Math Comput 2005, 163: 295–308. 10.1016/j.amc.2004.02.021
Yang QZ: On a generalized system for relaxed cocoercive variational inequalities and projection methods. J Optim Theory Appl 2006, 130: 545–547.
Peng JW, Zhu DL: A new system of generalized mixed quasi-variational inclusion with ( H , η )-monotone operators. J Math Anal Appl 2007, 327: 157–187.
Nadler SB: Multi-valued contraction mappings. Pac J Math 1969, 30: 475–486.
Acknowledgements
The author thanks to the guidance and support of my supervisor Pro. Li-Wei Liu who taught at the department of mathematics in Nanchang university. The author thanks the anonymous referees for reading this article carefully, providing valuable suggestions and comments. The work was supported by the National Science Foundation of China (No.10561007) and Science and Technology Research Project of Education Department in Jiangxi province (GJJ10269).
Author information
Authors and Affiliations
Corresponding author
Additional information
Competing interests
The authors declare that they have no competing interests.
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 2.0 International License (https://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
About this article
Cite this article
Cao, HW. A new system of generalized quasi-variational-like inclusions with noncompact valued mappings. J Inequal Appl 2012, 41 (2012). https://doi.org/10.1186/1029-242X-2012-41
Received:
Accepted:
Published:
DOI: https://doi.org/10.1186/1029-242X-2012-41