Hindawi Publishing Corporation Abstract and Applied Analysis Volume 2009, Article ID 341679, 16 pages doi:10.1155/2009/341679 Research Article Solvability of a Higher-Order Three-Point Boundary Value Problem on Time Scales Yanbin Sang Department of Mathematics, North University of China, Taiyuan, Shanxi 030051, China Correspondence should be addressed to Yanbin Sang, sangyanbin@126.com Received 3 August 2009; Revised 17 October 2009; Accepted 19 November 2009 Recommended by Ferhan Atici We consider a higher-order three-point boundary value problem on time scales. A new existence result is first obtained by using a fixed point theorem due to Krasnoselskii and Zabreiko. Later, under certain growth conditions imposed on the nonlinearity, several sufficient conditions for the existence of a nonnegative and nontrivial solution are obtained by using Leray-Schauder nonlinear alternative. Our conditions imposed on nonlinearity are all very easy to verify; as an application, some examples to demonstrate our results are given. Copyright q 2009 Yanbin Sang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1. Introduction We are concerned with the following even-order three-point boundary value problem on time scales T: 2n −1n yΔ t f yσ t , 2i 2i1 2i αi1 yΔ η βi1 yΔ a yΔ a, t ∈ a, b ⊂ T, 2i 2i γi1 yΔ η yΔ σb, 2n −1n yΔ t f t, yσ t , 2i 2i1 2i αi1 yΔ η βi1 yΔ a yΔ a, 0 ≤ i ≤ n − 1, t ∈ a, b ⊂ T, 2i 2i γi1 yΔ η yΔ σb, 0 ≤ i ≤ n − 1, 1.1 1.2 n ≥ 1, a < η < σb; we assume that σb is right dense so that σ j b σb for j ≥ 1 and that for each 1 ≤ i ≤ n, αi , βi , γi coefficients satisfy the following condition: σb − γi η γi − 1 a − βi , H 0 ≤ αi < σb − η βi ≥ 0, 0 < γi < σb − a βi . η − a βi 1.3 2 Abstract and Applied Analysis Throughout this paper, we let T be any time scale and let a, b be a subset of T such that a, b {t ∈ T : a ≤ t ≤ b}. Some preliminary definitions and theorems on time scales can be found in 1–5 which are excellent references for the calculus of time scales. In recent years, there is much attention paid to the existence of positive solution for second-order multipoint and higher-order two-point boundary value problems on time scales; for details, see 6–16 and references therein. However, to the best of our knowledge, there are not many results concerning multipoint boundary value problems of higher-order on time scales; we refer the readers to 17–20 for some recent results. We would like to mention some results of Anderson and Avery 17, Anderson and Karaca 18, Han and Liu 19, and Yaslan 20. In 17, Anderson and Avery studied the following even-order three-point BVP: n −1n xΔ∇ t λhtfxt, i xΔ∇ a 0, i t ∈ a, c ⊂ T, i xΔ∇ c βxΔ∇ b, 0 ≤ i ≤ n − 1. 1.4 They have studied the existence of at least one positive solution to the BVP 1.4 using the functional-type cone expansion-compression fixed point theorem. In 18, Anderson and Karaca were concerned with the dynamic three-point boundary 2n value problem 1.2 and the eigenvalue problem −1n yΔ t λft, yσ t with the same boundary conditions where λ is a positive parameter. Existence results of bounded solutions of a noneigenvalue problem were first established as a result of the Schauder fixed point theorem. Second, the monotone method was discussed to ensure the existence of solutions of the BVP 1.2. Third, they established criteria for the existence of at least one positive solution of the eigenvalue problem by using the Krasnosel’skii fixed point theorem. Later, they investigated the existence of at least two positive solutions of the BVP 1.2 by using the Avery-Henderson fixed point theorem. In 19, Han and Liu studied the existence and uniqueness of nontrivial solution for the following third-order p-Laplacian m-point eigenvalue problems on time scales: ∇ λf t, ut, uΔ t 0, φp uΔ∇ αu0 − βuΔ 0 0, uT t ∈ 0, T , 1.5 m−2 ai uξi , uΔ∇ 0 0, i1 where φp s is p-Laplacian operator, that is, φp s |s|p−2 s, p > 1, λ > 0 is a parameter, and 0 < ξ1 < · · · < ξm−2 < ρT . They obtained several sufficient conditions of the existence and uniqueness of nontrivial solution of the BVP 1.5 when λ is in some interval. Their approach was based on the Leray-Schauder nonlinear alternative. Very recently, Yaslan 20 investigated the existence of solutions to the nonlinear evenorder three-point boundary value problem on time scales T: 2n −1n yΔ t f t, yσt , yΔ 2i1 t1 0, αyΔ σt3 βyΔ 2i t ∈ t1 , t3 ⊂ T, 2i1 σt3 yΔ 2i1 t2 1.6 Abstract and Applied Analysis 3 for 0 ≤ i ≤ n − 1, where α > 0 and β > 1 are given constants. On the one hand, the author established criteria for the existence of at least one solution and of at least one positive solution for the BVP 1.6 by using the Schauder fixed point theorem and Krasnosel’skii fixed point theorem, respectively. On the other hand, the author investigated the existence of multiple positive solutions to the BVP 1.6 by using Avery-Henderson fixed point theorem and Leggett-Williams fixed point theorem. In this paper, motivated by 21, firstly, a new existence result for 1.1 is obtained by using a fixed point theorem, which is due to KrasnoseÍskı̆ and Zabreı̆ko 22. Particularly, f may not be sublinear. Secondly, some simple criteria for the existence of a nonnegative solution of the BVP 1.2 are established by using Leray-Schauder nonlinear alternative. Thirdly, we investigate the existence of a nontrivial solution of the BVP 1.2; our approach is also based on the application of Leray-Schauder nonlinear alternative. Particularly, we do not require any monotonicity and nonnegativity on f. Our conditions imposed on f are all very easy to verify; our method is motivated by 1, 21, 23, 24. 2. Preliminaries To state and prove the main results of this paper, we need the following lemmas. Lemma 2.1 see 18. For 1 ≤ i ≤ n, let Gi t, s be Green’s function for the following boundary value problem: −yΔ t 0, 2 t ∈ a, b ⊂ T, αi y η βi yΔ a ya, γi y η yσb, 2.1 and let di γi − 1a − βi 1 − αi σb ηαi − γi . Then, for 1 ≤ i ≤ n, Gi t, s ⎧ ⎨Gi1 t, s, a ≤ s ≤ η, ⎩G t, s, i2 η < s ≤ b, 2.2 where ⎧ σs ≤ t, 1 ⎨ γi t − η σb − t σs βi − a , Gi1 t, s di ⎩ γ σs − η σb − σs t β − a α η − σb t − σs, t ≤ s, i i i ⎧ 1 ⎨ σs1 − αi αi η βi − a σb − t γi η − a βi t − σs, σs ≤ t, Gi2 t, s di ⎩ t1 − α α η β − aσb − σs, t ≤ s. i i i 2.3 Lemma 2.2 see 18. Under condition H, for 1 ≤ i ≤ n, Green’s function Gi t, s in 2.2 possesses the following property: Gi t, s > 0, t, s ∈ a, σb × a, b. 2.4 4 Abstract and Applied Analysis Lemma 2.3 see 18. Assume that H holds. Then, for 1 ≤ i ≤ n, Green’s function Gi t, s in 2.2 satisfies 1 η−aβi σb−σs , Gi t, s ≤ max Gi a, s, Gi σs, s, di t, s ∈ a, σb×a, b, 0 < γi ≤ 1, Gi t, s ≤ max{Gi σb, s, Gi σs, s}, t, s ∈ a, σb × a, b, 1 < γi < σb − a βi . η − a βi 2.5 Lemma 2.4 see 18. Assume that condition H is satisfied. For G as in 2.2, take H1 t, s : G1 t, s and recursively define Hj t, s σb 2.6 Hj−1 t, rGj r, sΔr a for 2 ≤ j ≤ n. Then Hn t, s is Green’s function for the homogeneous problem: −1n yΔ t 0, 2n 2i 2i1 2i αi1 yΔ η βi1 yΔ a yΔ a, t ∈ a, b ⊂ T, 2i 2i γi1 yΔ η yΔ σb, Lemma 2.5 see 18. Assume that H holds. If one defines K Hn t, s in Lemma 2.4 satisfies the following inequalities: 0 ≤ Hn t, s ≤ KGn ·, s, n−1 0 ≤ i ≤ n − 1. j1 Kj , 2.7 then the Green function t, s ∈ a, σb × a, b, 2.8 where Kj σb Gj ·, sΔs > 0, 1 ≤ j ≤ n. 2.9 a Lemma 2.6 see 22. LetX be a Banach space and let F : X → X be completely continuous. If there exists a bounded and linear operator A : X → X such that 1 is not an eigenvalue of A and lim u → ∞ Fu − Au 0, u 2.10 then F has a fixed point in X. Lemma 2.7 see 25. Let X be a real Banach space, let Ω be a bounded open subset of X, 0 ∈ Ω, and let F : Ω → X be a completely continuous operator. Then either there exist x ∈ ∂Ω, λ > 1 such that Fx λx or there exists a fixed point x∗ ∈ Ω. Abstract and Applied Analysis 5 Suppose that B denotes the Banach space Ca, σb with the norm y supt∈a,σb |yt|. 3. Existence Results In this section, we apply Lemmas 2.6 and 2.7 to establish some existence criteria for 1.1 and 1.2. Theorem 3.1. Suppose that condition H holds, and f lims → ∞ fs/s m. If : R → R is continuous with ⎤−1 ⎡ n |m| < d ⎣ Kj ⎦ , 3.1 j1 then the BVP 1.1 has a solution y∗ , and y∗ / 0 when f0 / 0. Proof. Define the integral operator F : B → B by Fyt σb Hn t, sf yσ s Δs 3.2 a for t ∈ a, σb. Obviously, the solutions of the BVP 1.1 are the fixed points of operator F. From the proof of Theorem 3.1 of 18, we can know that F : B → B is completely continuous. In order to apply Lemma 2.6, we consider the following BVP: −1n yΔ t myσ t, 2n 2i 2i1 2i αi1 yΔ η βi1 yΔ a yΔ a, t ∈ a, b ⊂ T, 2i 2i γi1 yΔ η yΔ σb, 0 ≤ i ≤ n − 1. 3.3 Define the integral operator A : B → B by Ayt m σb Hn t, syσ sΔs 3.4 a for t ∈ a, σb. Then it is easy to check that A : B → B is completely continuous so bounded linear operator and that solutions of the BVP 3.3 are the fixed points of operator A and conversely. First, we claim that 1 is not an eigenvalue of A. In fact, if m 0, then it is obvious that the BVP 3.3 has no nontrivial solution. 6 Abstract and Applied Analysis If m / 0 and the BVP 3.3 has a nontrivial solution y, then y > 0, and so y Ay σb σ sup m Hn t, sy sΔs a t∈a,σb σb σ |m| sup Hn t, sy sΔs a t∈a,σb ≤ |m| σb KGn ·, syσ sΔs 3.5 a ⎛ ⎞ n ≤ |m|⎝ Kj ⎠y j1 <d· 1 y y, d which is impossible. So, 1 is not an eigenvalue of A. Next, we will show that F y − A y lim 0. y y → ∞ 3.6 In fact, for any > 0, since lims → ∞ fs/s m, there must exist a number Y1 > 0 such that fs − ms < |s|, |s| > Y1 . 3.7 Let M maxfs. |s|≤Y1 3.8 Then for any y ∈ B and y > Y Y > 0, we distinguish the following two cases. Case 1 Y < Y1 . In this case, choose Y such that M |m|Y1 < . Y 3.9 Thus, when s ∈ a, σb and |yσ s| ≤ Y1 , we have σ f y s − myσ s ≤ f yσ s |m|yσ s ≤ M |m|Y1 < Y < y, 3.10 Abstract and Applied Analysis 7 which together with 3.7 implies that y > Y. σ f y s − myσ s < y, 3.11 Case 2 Y ≥ Y1 . In this case, when s ∈ a, σb, from 3.7, we see that σ f y s − myσ s < yσ s ≤ y. 3.12 Thus, we can deduce from 3.11 and 3.12 that for any y ∈ B and y > Y σ f y s − myσ s < y, ∀s ∈ a, σb. 3.13 From 3.13, we have F y − A y ≤ σb σ σ sup Hn t, s f y s − my s Δs a t∈a,σb σb sup Hn t, sf yσ s − myσ sΔs t∈a,σb a ⎛ ⎞ n ≤ y⎝ Kj ⎠ 3.14 j1 y. d that is to say, F y − A y lim 0. y y → ∞ 3.15 Then, it follows from Lemma 2.6 that F has a fixed point y∗ ∈ B. In other words, y∗ is a solution of the BVP 1.1. Moreover, we can assert that y∗ is nontrivial when f0 / 0. In fact, if f0 / 0, then f0, −1n 0Δ 0 / 2n 3.16 that is, 0 is not a solution of the BVP 1.1. Corollary 3.2. Assume that condition H holds, and f : 0, ∞ → 0, ∞ is continuous with lims → ∞ fs/s 0. Then the BVP 1.1 has a nonnegative solution. 8 Abstract and Applied Analysis Proof. Let f ∗ s ⎧ ⎨fs, s ≥ 0, ⎩f−s, 3.17 s < 0, then f ∗ : R → 0, ∞ is continuous, and from lims → ∞ fs/s 0, we know that f ∗ s 0. s → ∞ s 3.18 lim Consider the following BVP: 2n −1n yΔ t f ∗ yσ t , 2i 2i1 2i αi1 yΔ η βi1 yΔ a yΔ a, t ∈ a, b ⊂ T, 2i 2i γi1 yΔ η yΔ σb, 0 ≤ i ≤ n − 1. 3.19 It follows from Theorem 3.1 that the BVP 3.19 has a solution y∗ , that is, Δ2n σ t f ∗ y∗ t , −1n y∗ Δ2i Δ2i Δ2i1 η βi1 y∗ αi1 y∗ a y∗ a, t ∈ a, b ⊂ T, Δ2i ∗ Δ2i γi1 y∗ η y σb, 0 ≤ i ≤ n − 1. 3.20 Since Hn t, s and f ∗ are nonnegative, we can get that y∗ ≥ 0 on a, σb. Consequently, from the definition of f ∗ , we have σ Δ2n t f y∗ t , −1n y∗ t ∈ a, b ⊂ T. 3.21 It follows from the boundary conditions of 3.20 and 3.21 that y∗ is a nonnegative solution of the BVP 1.1. Remark 3.3. In Corollary 3.2, we only need that lims → ∞ fs/s 0. Thus, f may not be sublinear. Theorem 3.4. Assume that condition H holds, and f : a, σb × 0, ∞ −→ 0, ∞ is continuous with ft, u > 0 for t, u ∈ a, σb × 0, ∞, ft, u ≤ ϕtgu on a, σb × 0, ∞ with g ≥ 0 continuous, and nondecreasing on 0, ∞ and ϕ : a, σb → 0, ∞ continuous ∃r > 0 with r > gr σb a ϕsKGn ·, sΔs, 3.22 3.23 3.24 Abstract and Applied Analysis 9 where K and Gn ·, s are defined in Lemmas 2.5 and 2.1, respectively. Then the BVP 1.2 has a nonnegative solution y1 with y1 < r. Proof. We consider the following boundary value problem: 2n −1n yΔ t λf ∗ t, yσ t , 2i 2i1 2i αi1 yΔ η βi1 yΔ a yΔ a, t ∈ a, b ⊂ T, 2i 2i γi1 yΔ η yΔ σb, 0 ≤ i ≤ n − 1. 3.25 where 0 < λ < 1, and f ∗ t, u ⎧ ⎨ft, u, u ≥ 0, ⎩ft, 0, u < 0. 3.26 Let y be any solution of 3.25. Then σb yt λ Hn t, sf ∗ s, yσ s Δs 3.27 a for t ∈ a, σb. We note that yt ≥ 0 for t ∈ a, σb. It follows from condition 3.23 in Theorem 3.4 that for t ∈ a, σb yt ≤ σb Hn t, sϕsg yσ s Δs a σb ≤ g y 3.28 ϕsKGn ·, sΔs. a Consequently, σb y ≤ g y ϕsKGn ·, sΔs, 3.29 a which together with the condition 3.24 in Theorem 3.4 implies that y / r. Let N : B → B be given by Nyt σb a Hn t, sf ∗ s, yσ s Δs. 3.30 10 Abstract and Applied Analysis It is easy to show that N : B → B is completely continuous. Let U {u ∈ B : u < r}. 3.31 Since y / r, any solution y ∈ ∂U of y λNy with 0 < λ < 1 cannot occur. Lemma 2.7 guarantees that N has a fixed point y1 in U. In other words, the BVP 1.2 has a solution y1 ∈ B with y1 < r. Theorem 3.5. Assume that condition H is satisfied. Suppose that ft, 0 ≡ / 0, t ∈ a, σb, f : a, σb × R → R is continuous, and there exist nonnegative integrable functions k, h such that f t, y ≤ kty ht, σb K t, y ∈ a, σb × R, Gn ·, sksΔs < 1. 3.32 a Then, the BVP 1.2 has at least one nontrivial solution y∗ ∈ B. Proof. Let AK σb Gn ·, shsΔs, a BK σb 3.33 Gn ·, sksΔs. a By hypothesis B < 1. Since ft, 0 / ≡ 0, there exists m, n ⊂ a, σb such that mint∈m,n |ft, 0| > 0. On the other hand, from the condition ht ≥ |ft, 0|, a.e. t ∈ a, σb, we know that A > 0. Let d A1 − B−1 , Ωd {y ∈ B : y < d}. For t ∈ a, σb, the operator T is defined by T yt σb Hn t, sf s, yσ s Δs, 3.34 a from the proof of Theorems 3.1 and 3.4, we have known that T : B → B is a completely continuous operator, and the BVP 1.2 has at least one nontrivial solution y∗ ∈ B if and only if y∗ is a fixed point of T in B. Abstract and Applied Analysis 11 Suppose y ∈ ∂Ωd , λ > 1 such that T y λy, then λd λy T y sup T yt t∈a,σb σb σ sup Hn t, sf s, y s Δs a t∈a,σb ≤K σb Gn ·, sf s, yσ s Δs 3.35 a ≤K σb Gn ·, s ksyσ s hs Δs a K σb Gn ·, sksyσ sΔs K σb a Gn ·, shsΔs a ≤ By A Bd A. Therefore λ − 1d ≤ A − 1 − Bd A − A 0, 3.36 which contradicts λ > 1. By Lemma 2.7, T has a fixed point y∗ ∈ Ωd . Noting ft, 0 / ≡ 0, the BVP 1.2 has at least one nontrivial solution y∗ ∈ B. This completes the proof. Corollary 3.6. Assume that condition H is satisfied. Suppose that ft, 0 ≡ / 0, t ∈ a, σb, f : a, σb × R → R is continuous, and there exist nonnegative integrable functions k, h such that f t, y ≤ kty ht, ⎡ ⎤−1 n kt < e ⎣ Kj ⎦ , t, y ∈ a, σb × R, 3.37 t ∈ a, σb. j1 Then, the BVP 1.2 has at least one nontrivial solution y∗ ∈ B. Proof. In this case, we have σb K a Gn ·, sksΔs < Ke σb ⎡ ⎤−1 σb n Gn ·, sΔs K ⎣ Kj ⎦ Gn ·, sΔs 1. 3.38 a By Theorem 3.5, this completes the proof. j1 a 12 Abstract and Applied Analysis Corollary 3.7. Assume that condition H is satisfied. Suppose that ft, 0 / ≡ 0, t ∈ a, σb, f : a, σb × R → R is continuous, and there exist nonnegative integrable functions k, h such that f t, y ≤ kty ht, t, y ∈ a, σb × R, n −1 ft, l < Kj lim max . |l| → ∞ t∈a,σb l j1 3.39 Then, the BVP 1.2 has at least one nontrivial solution y∗ ∈ B. Proof. Let ⎤ ⎡⎛ ⎞−1 n ft, l ⎥ 1⎢ 1 ⎣⎝ Kj ⎠ − lim max ⎦, |l| → ∞ t∈a,σb 2 l j1 3.40 then, there exists c > 0 such that ⎡⎛ ⎤ ⎞−1 n ⎢ ft, l ≤ ⎣⎝ Kj ⎠ − 1 ⎥ ⎦|l|, t, l ∈ a, σb × R \ −c, c. 3.41 j1 Set ! max ft, l | t, l ∈ a, σb × −c, c , M 3.42 and it follows from 3.41 and 3.42 that ⎡⎛ ⎤ ⎞−1 n ⎥ ft, l ≤ ⎢ ⎣⎝ Kj ⎠ − 1 ⎦|l| M, t, l ∈ a, σb × R. 3.43 j1 By Corollary 3.6, we can deduce that Corollary 3.7 is true. 4. Two Examples In the section, we present two examples to explain our results. Example 4.1. Let T R0, 1 ∪ {1, 2, 3, 4, 5} ∪ 6, 7, and consider the following BVP: 2 −yΔ t f yσ t , " # 3 2 2 y yΔ 0 y0, 5 3 3 t ∈ 0, 5 ⊂ T, " # 2 1 y yσ5, 6 3 4.1 Abstract and Applied Analysis 13 where fy 17737/89902y 1/101. It is easy to check that σb − γ1 η γ1 − 1 a − β1 6 − 1/6 · 2/3 1/6 − 10 − 2/3 29 3 , 0 < α1 < 5 σb − η 6 − 2/3 24 β1 2 > 0, 3 0< σb − a β1 1 6 − 1 2/3 γ1 < 5, 6 η − a β1 2/3 − 0 2/3 4.2 and therefore, the condition H is satisfied. By computation, we can get that 146 d1 γ1 − 1 a − β1 1 − α1 σb η α1 − γ1 , 45 ⎧ 2 ⎪ ⎨G11 t, s, 0 ≤ s ≤ , 3 G1 t, s 2 ⎪ ⎩G1 t, s, < s ≤ 5, 2 3 4.3 where # &" # ⎧% 1 " 2 2 ⎪ ⎪ t − σ5 − t σs , σs ≤ t, ⎪ 3 3 45 ⎨ 6 G11 t, s # &" # " # % " 146 ⎪ ⎪ ⎪ ⎩ 1 σs − 2 6 − σs t 2 3 2 − 6 t − σs, t ≤ s, 6 3 3 5 3 # & " # " ⎧% 3 2 2 1 2 2 3 ⎪ ⎪ × − t σs 1 − 6 t − σs, ⎪ 5 5 3 3 6 3 3 45 ⎨ G12 t, s %" # & 146 ⎪ ⎪ ⎪ ⎩ t 1 − 3 3 × 2 2 6 − σs, 5 5 3 3 4.4 σs ≤ t, t ≤ s. From the proof of Lemma 2.5 in 18, we can get that 1 η − a β1 σb − σs G1 σs, s, G1 ·, s max G1 0, s, G1 σs, s, d1 4.5 and for γ1 1/6 ∈ 0, 1 and α1 3/5 ∈ 0, 1, we have K1 45 146 2/3 % " % " # & # &" # 45 1 3 1 2 2 3 2 2 s 1− s− 6−s s −0 ds × −0 6−sds 6 3 3 146 2/3 5 5 3 3 0 % " # & 5 45 3 3 2 2 × 6 − s 1 s 1 1 − 146 5 5 3 3 s1 89902 . 17739 4.6 14 Abstract and Applied Analysis Thus, we can obtain that f y 17737/89902y 1/101 17737 17739 lim lim < d K1−1 . y→∞ y y→∞ y 89902 89902 4.7 By Theorem 3.1, it is easy to get that the BVP 4.1 has a solution y∗ . Example 4.2. Let us introduce an example to illustrate the usage of Theorem 3.5. Let n 2, T {2/3n : n ∈ N0 } ∪ {0} ∪ 1, 2, a 8/27, η 4/9, b 2/3, α1 1/2, β1 1/9, α2 1/10, β2 7/27, γ1 3/2, and γ2 2. Then condition H is satisfied. Green’s function G1 t, s in Lemma 2.1 is G1 t, s ⎧ ⎪ ⎪ ⎪ ⎨G11 t, s, 4 8 ≤s≤ , 27 9 ⎪ ⎪ ⎪ ⎩G12 t, s, 4.8 2 4 <s≤ , 9 3 where G11 t, s G12 t, s # &% & ⎧% " 4 3 1 8 3 ⎪ ⎪ t − 1 − t s − , ⎪ ⎪ 9 2 9 27 ⎨ 2 3 s ≤ t, 2 27 &" #" # % " # # " 4⎪ ⎪ ⎪ 4 1 8 3 3 3 3 1 4 ⎪ ⎩ s− −1 t − s , t ≤ s, 1− s t − 2 2 9 2 9 27 2 9 2 # # & " #" ⎧% " 1 1 4 1 8 3 4 8 1 3 3 ⎪ ⎪ s 1− × − − s , t− 1−t ⎪ ⎪ 2 2 9 9 27 2 9 27 9 2 ⎨ 2 27 # &" # %" 4⎪ ⎪ ⎪ 1 4 1 8 3 1 ⎪ ⎩ t 1− × − 1− s , 2 2 9 9 27 2 4.9 3 s ≤ t, 2 t ≤ s. Green’s function G2 t, s in Lemma 2.1 is G2 t, s ⎧ ⎪ ⎪ ⎪ ⎨G21 t, s, ⎪ ⎪ ⎪ ⎩G22 t, s, 4 8 ≤s≤ , 27 9 2 4 <s≤ , 9 3 4.10 Abstract and Applied Analysis 15 where G21 t, s G22 t, s # &% & ⎧% " 3 7 8 4 ⎪ ⎪ ⎪ ⎪ 2 t − 9 1 − t 2 s 27 − 27 , 54 ⎨ # &" # " #" # % " 5⎪ ⎪ ⎪ 4 3 7 8 1 4 3 3 ⎪ ⎩ 2 s− 1− s t − −1 t− s , 2 9 2 27 27 10 9 2 3 s ≤ t, 2 t ≤ s, # & " #" # ⎧% " 1 1 4 7 8 4 8 7 3 3 ⎪ ⎪ s 1 − × − − t− s , 1−t2 ⎪ ⎪ 10 10 9 27 27 9 27 27 2 ⎨ 2 54 # &" # %" 4⎪ ⎪ ⎪ 1 4 7 8 3 1 ⎪ ⎩ t 1− × − 1− s , 10 10 9 27 27 2 3 s ≤ t, 2 t ≤ s. 4.11 Since s ∈ a, γ1 η − a β1 − α1 η − β1 a/1 − α1 8/27, 19/27, by using the cases in the proof of Lemma 2.5 of 18, we can know that G1 ·, s G1 σ2/3, s. Therefore, we have K1 133/324. Set ft, y t|y| sin y t3 − 2 sin t, kt t, and ht t3 2 sin t. Then it is easy to prove that f t, y ≤ kty ht, t, y ∈ a, σb × R. 4.12 On the other hand, since s ∈ a, γ2 η − a β2 − α2 η − β2 a/1 − α2 8/27, 218/243, we can know that G2 ·, s G2 1, s by using the cases in the proof of Lemma 2.5 of 18. Therefore, we have σb a G2 ·, sksΔs 6 · 11 · 16 · 47 . 5 · 273 4.13 Thus σb K a ⎛ ⎞ σb 2−1 133 6 · 11 · 16 · 47 ⎝ ⎠ · Kj < 1. G2 ·, sksΔs G2 ·, sksΔs 324 5 · 273 a j1 4.14 Hence, by Theorem 3.5, the BVP 1.2 has at least one nontrivial solution y∗ . Acknowledgment Project supported by the Youth Science Foundation of Shanxi Province 2009021001-2. 16 Abstract and Applied Analysis References 1 R. P. Agarwal and D. O’Regan, “Nonlinear boundary value problems on time scales,” Nonlinear Analysis: Theory, Methods & Applications, vol. 44, no. 4, pp. 527–535, 2001. 2 F. M. Atici and G. Sh. 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