Abstract

In this paper, we firstly discuss the existence of the least energy sign-changing solutions for a class of p-Kirchhoff-type problems with a -linear growth nonlinearity. The quantitative deformation lemma and Non-Nehari manifold method are used in the paper to prove the main results. Remarkably, we use a new method to verify that . The main results of our paper are the existence of the least energy sign-changing solution and its corresponding energy doubling property. Moreover, we also give the convergence property of the least energy sign-changing solution as the parameter .

1. Introduction and the Main Results

In this paper, we are devoted to investigating the existence of the least energy sign-changing solutions for the following p-Kirchhoff-type problem with a (2p-1)-linear growth nonlinearity:where is a bounded domain in , , , is the first eigenvalue of the following problem:

In fact, the related problems have been studied extensively, especially on the existence of the positive solutions, multiple solutions, ground state solutions, and least energy sign-changing solutions. In [1], Li and Sun studied the existence and multiplicity of solutions for the Kirchhoff equations with asymptotically linear nonlinearities; the mountain pass theorem was used in the paper. Guo, Ma, and Zhang [2] studied a class of autonomous Kirchhoff-type equation. By a simple transformation, they found that the solutions of autonomous Kirchhoff-type equation or system could be obtained by using the known solutions of the corresponding local equation or system, which is very interesting. In [3], Ying Li and Lin Li considered the existence and multiplicity of solutions to a class of p(x)-Laplacian-like equations. They introduced a revised Ambrosetti-Rabinowitz condition and obtained that the problem had a nontrivial solution and infinitely many solutions, respectively. Meanwhile, in [4], Luca Vilasi proved an eigenvalue theorem for a stationary p(x)-Kirchhoff problem by using variational techniques, and the author also provided an estimate for the range of such eigenvalues. For more details, we refer the reader to [530].

In [31, 32], the authors studied the following Kirchhoff-type problems in bounded domains:under different assumptions on , the authors mainly use the quantitative deformation lemma and the degree theory to get the existence of the least energy sign-changing solution and its corresponding convergence property as the parameter From the assumptions on , we can easily find that both in [31, 32] satisfies 3-superlinear growth at infinity and superlinear growth at zero.

Later, some scholars made some expanding work; we can find some details in [33]. In [33], we know that the nonlinearity satisfies -superlinear growth condition at infinity.

Motivated by the above works, a natural question is that if there exists a ground state sign-changing solution for problem (1). However, up to now, no paper has appeared in the literature which discusses the existence and convergence property of the solution for the p-Kirchhoff-type problem with a -linear growth nonlinearity. This paper attempts to fill this gap in the literature.

Throughout this paper, we will make full use of the following notations. Let be the usual Sobolev space equipped with the following norm: denotes the usual Lebesgue space norm. is the best Sobolev constant for the embedding of in ; that is,

From the above definition, we give the energy functional corresponding to problem (1) byClearly, is well defined on and is of class. For each , by a simple calculation, we haveObviously, the critical points of are corresponding to the weak solutions of problem (1). If is a sign-changing solution of problem (1), then

(i) is a solution of problem (1), that is, is a critical point of ;

(ii) , where .

For , from (6) and (7), we have

When , problem (1) reduces to the following problem:

The corresponding energy functional is defined by Also, we can compute that

For , problem (1) is called a nonlocal problem since the appearance of the nonlocal term . The differences posed by the nonlocal term make the method in solving problem (11) cannot be applied to solve problem (1), which makes the study of our paper very interesting and meaningful.

In our paper, we restrict in the following sets to find the ground state sign-changing solutions of (1) and (11),and we define and .

To get the ground state solutions, we define the following sets:and consider the following minimization problem:

Since , we can immediately get . The main results of the paper are described as follows.

Theorem 1. For and , problem (1) has at least one ground state sign-changing solution, which precisely has two nodal domains. Moreover, .

Theorem 2. For each , for any sequence small enough with as , there exists a subsequence still denoted by , such that convergent to strongly in , where is a ground state sign-changing solution of problem (11), which changes sign only once.

Our paper is organized as follows. In Section 2, some preliminary lemmas are given to prove the main results. In Sections 3 and 4, we are devoted to proving the main results of the paper.

2. Some Critical Preliminaries

The following several lemmas are crucial to prove our main results.

Lemma 3. If , , satisfies andthen there exists a unique pair of positive numbers such that
(i) ;
(ii) .

Proof. (i) If , then from (7), (9), and (10), we haveandLet and , the above equations correspond to the following system:Obviously, if we can prove that system (20) has the unique solution , then is the unique solution for (18) and (19).
LetFor , we have . Since , then Similarly, we haveFrom (21)-(23), we have , and is the unique solution for system (20). Accordingly, is the unique positive solution for (18) and (19). Thus, (i) is proved.
(ii) Next, we give the proof of (ii).
From (6), we haveBy a simple computation, we haveandFrom , we haveandWe consider the Hessian matrix of ; then from (17), we have The above deduction implies that is a maximal point of for . Since we cannot get the maximal point of on the boundary of , is the unique maximal point; that is,

Lemma 4. Assume that and , then (17) holds.

Proof. For , we haveSince , we have . Thus, we have

Lemma 5. Assume that , with and , there exists a unique pair such that .

Proof. If with and , we haveSince , thenFrom Lemma 3, there is a unique pair of positive numbers such that , which implies that is the solution of system (20). Then, we haveTherefore, we have . Similarly, we have . Thus, there exists a unique pair such that .

Lemma 6. If for any with , there exists a unique such that . Moreover, for all and .

Proof. If and satisfies , implies thatThus, there exists a unique satisfying (35). From (6), we haveBy a simple deduction, we haveThus, attains its maximal point at . In other words, we have for all and .

Lemma 7. Assume ; we have that
(i) if , is attained by some and is a constant sign critical point of , where is given by (5);
(ii) if , is attained by some and is a sign-changing critical point of .

Proof. (i) Firstly, we will show that for all , there exists such that , which implies . From (5), we know that there exists such that For , we haveThus, we have .
For each , it follows from and (5) thatThen, . Thus, we havethat is, and is coercive and bounded below on for and .
Let be a minimizing sequence for . From and , we assume that in for all . Since is coercive and bounded below on , the sequence is bounded in , so that, up to subsequences, in and . Next, we will prove that strongly in . We suppose by contradiction that . Therefore, we haveIf , the above inequality makes a contradiction. Thus, we have in . From the fact that , we have . By Lemma 6, there exists a unique such that and for all Thus, we havewhich leads to a contradiction. Therefore, we have , strongly in and . Then, by a standard argument, which is similar to the discussion in [34], we can deduce that is a constant sign critical point of .
(ii) From a similar deduction as (i), we know that for , there exists such thatObviously, if such that satisfies (43), then also satisfies (43). Therefore, we assume that a.e. in . We let and define for all , where and . Then, from (43), we haveLet ; we can obtain that and andthat is,Similarly, we also haveBy Lemma 3, we know that for .
Assume that is a minimizing sequence for , such that . Since is coercive on , the sequence is bounded in ; going if necessary to a subsequence, still denoted by , we can assume that there exists a such that for sufficiently large,From , we have ; that is,Therefore,In the same way, we have and Passing to the limit, we havewhich implies that andFrom , Lemmas 3 and 5, there exists a unique pair such thatFrom the definition of , we haveThus, , , and , is the required minimizer.
Next, we will prove that is indeed a sign-changing solution; that is, . We mainly use the quantitative deformation lemma [35] to prove the results.
If , there exists and , such thatLet , , and . It follows from Lemma 3 thatLet and ; there exists a deformation such that
(i) if ;
(ii) ;
(iii) .
From (56), Lemma 3 and (ii), we can easily getWe prove that , which contradicts the definition of . We define andLemma 3 and the degree theory yield . From (56), we know that on . Consequently, we have . Therefore, for some ; that is, , which is a contradiction. From this point, is a sign-changing critical point of and .

3. The Existence of the Sign-Changing Solutions

In this part, we are devoted to proving Theorem 1.

Proof of Theorem 1. In view of Lemma 7, we know that for and , there exists a such that and ; that is, is a ground state sign-changing solution for problem (1). Then by Lemma 4, we have thatwhich impliesThen from Lemma 6, there exist such that . Therefore, we haveTherefore, the energy doubling property is proved.
Next, we prove that changes sign only once; that is, has exactly two nodal domains. We assume by contradiction that with and for .
Since , we can getThen, by Lemma 5, there exists a pair such that and .
From , , and , we havewhich leads to a contradiction; thus, has exactly two nodal domains.

4. The Convergence Property of as

In this part, we regard as a small parameter in (1) and discuss the convergence property of the least energy sign-changing solution , where and changes sign only once.

Proof of Theorem 2. We choose a nonzero function and such that andThus, for any , we have . It follows from Lemma 5 that there is a unique pair such that . Thus, we haveFor any sequence with as , there exists such that is a ground state sign-changing critical point of andThe above inequality shows that is bounded in ; then there exists a subsequence of , still denoted by , such that weakly in . By the compactness of the embedding for , using a standard argument, we have that in and . Moreover, we have that for all ,which implies thatSecondly, in the Proof of Theorem 1, is allowed; then, there exists a such thatand is a sign-changing solution for (11) which changes sign only once. Similarly, we can pick up which is independent of such thatAccording to Lemma 3, there exists a unique pair of positive numbers such that .
Let ; we know thatIn the same way, we can obtain thatIt follows from Lemma 5 that for all , there exists a unique pair such that . Then, for any sequence with as , we have as ,According to , we have From , we have Combining (74) with (75), we have that as , , . Lastly, we only need to show ; then by (68), is a ground state sign-changing solution for (11), which changes sign only once. In fact,Then, the proof of Theorem 2 is complete.

Data Availability

The data used to support the findings of this study are included within the article.

Conflicts of Interest

The authors declare that they have no conflicts of interest regarding the publication of this paper.

Acknowledgments

This research was supported by the Outstanding Youth Foundation of North University of China (No. JQ201604), the Program for the Innovative Talents of Higher Education Institutions of Shanxi, the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (201802085), and the Natural Science Foundation of Shanxi Province, China (201801D121158).