Articles

Recepción: 01 Junio 2021
Revisado: 25 Noviembre 2021
Publicación: 22 Febrero 2022
DOI: https://doi.org/10.15388/namc.2022.27.26363
Financiamiento
Fuente: National Natural Science Foundation of China
Nº de contrato: (12101086, 11871302)
Beneficiario: Existence of multiple positive solutions for a class of infinite-point singular p-Laplacian fractional differential equation with singular source terms
Financiamiento
Fuente: Changzhou Science and technology planning project
Nº de contrato: (CJ20210133)
Beneficiario: Existence of multiple positive solutions for a class of infinite-point singular p-Laplacian fractional differential equation with singular source terms
Financiamiento
Fuente: Project of Shandong Province Higher Educational Science and Technology Program
Nº de contrato: J18KA217
Beneficiario: Existence of multiple positive solutions for a class of infinite-point singular p-Laplacian fractional differential equation with singular source terms
Abstract: Based on properties of Green’s function and by Avery–Peterson fixed point theorem, the existence of multiple positive solutions are obtained for singular p-Laplacian fractional differential equation with infinite-point boundary conditions, and an example is given to demonstrate the validity of our main results.
Keywords: fractional differential model, multiple positive solutions, Avery–Peterson fixed point.
Introduction
In this paper, we will devote to considering the following infinite-point singular p-Laplacian fractional differential equation:
(1)with infinite-point boundary condition
(2)Where
Laplacian operator φp is defined as
and 0
1
and
has singularity at
is the standard Riemann-Liouville derivative,
is the estandard Caputo derivative.
Fractional-order system may have additional attractive feature over the integer-ordersystem. For example, the analytical solutions of the systems

are
respectively. Obviously, the integer-ordersystem is unstable for a
, the fractional dynamic system is stable as 0 < a.Moreover, fractional-order systems have been shown to be more accurate and realisticthan integer-order models, and it also provides an excellent tool to describe the hereditaryproperties of material and processes, particularly, in viscoelasticity, electrochemistry,porous media, and so on. As a result, there has been a significant development in thestudy of fractional differential equations in recent years, readers can refer to [2, 4–10,15–17, 21–24]. Jong [12] studied the following p-Laplacian fractional differential equations:
(3)with m-point boundary condition
(4)Where
is a fixed integer,
permits singularities with respect to both thetime and space variables. According to introducing height functions, the author obtainedthe existence and multiplicity of positive solution theorems, and Zhang and Zhai obtainedthe existence and uniqueness of positive solution for this equation in [18]. In [19], Zhangand Liu investigated the following infinite-point fractional differential equation
:

Laplacian operator is defined as 

The authors obtained the existence and uniqueness of solutions byusing the fixed point theorem for mixed monotone operators. Jong [11] obtained theexistence and uniqueness of positive solutions by the Banach contraction mapping principlefor equation (3), (4). In [20], the author considered following fractional differential equation:

with infinite-point boundary condition

where
is a Caratheodory function,
and
are two monotic sequence with lim 
is the standard Riemann–Liouville derivative. Theauthors established the existence of at least one solution for this equation by Mawhin’s continuation theorem. Motivated by the excellent results above, in this paper, the existence of multiplepositive solutions are obtained for a singular infinite-point p-Laplacian boundary valueproblems. Compared with [19], the equation in this paper is p-Laplacian fractional differentialequation, and the method which we used in this paper is Avery–Peterson fixed pointtheorem. Compared with [12], fractional derivative is involved in the nonlinear terms for BVP (1), (2), and multiple positive solutions are obtained for the BVP (1), (2).
Preliminaries and lemmas
In this section, we introduce definitions and preliminary results, which are used through out this paper. First, we let
[0; 1] be the Banach space with the maximum norm

In this section, we introduce definitions and preliminary results, which are used throughout this paper. First, we let
[0; 1] be the Banach space with the maximum norm
then we list a condition below to be used later in the paper.
(HO)
and for all
there exists an funcion
, such that 
Now, we state some lemmas, which are basic and used in this paper.
(See [13, 16].) Assume that
, then 

Lemma 2. Assume that
, then 

where n is the least integer greater than or equal to 
Lemma 3. See [3, Thm. 1.2.7].) Let
, then H is a relatively compact set i fand only if
H´ is equicontinuous, and H´(t) is a relatively compact set for any 
There exists to
such that
is a relatively compact set on E.
i) H is equicontinuous, and H´(t) is a relatively compact set for any
;
(ii) There exists
such that is a relatively compact set on E.
Lemma 4. (See [1, 14].) Let P be a cone of
be nonnegative continuous concave funcional on P
be nonnegative continuous concave funcional on P, and
be a nonnegative continuos funcional on P
such that for some positive numbers L
Let A:
is completely continuous and there exist positive nembers e, c, d, with e< c such that following conditions are satisfied:

Then A has at least three fixed points x1, x2, x3 such that
and 
Lemma 5. Given y
then the solution of the BVP
(5)with boundary condition (2) can be expressed by
(6)where
(7)in which
(8)
(9)Proof: By Means of Lemma I we reduce(5) to an equivalent equation

for
From 
we have
Consequently, we get.

hence, we have
(10)On the other hand,
, combining with (10),we get

Therefore, G(t; s) is as (7). By simple calculation we have

Lemma6. let
then the BVP (1), (2) has a unique solution.
(11)where G(t; s) is as (6), and
(12)in which
(13)
(14)Proof. Let
Consider the boundary value problem
(15)By means of the Lemma 2 we reduce (15) to an equivalent integral equation
[16]for
From
we have
Consequently,we get
(16)for
. From
we have
. Con sequently, we get 
On the other hand,
and combining with (16), we get 

where
is as (13), P(s) is as 14. Hence,

Therefore, H(t,s) is as 12
Lemma7.Take
with
then
where 


Proof. By direct calculation we get 
and so is nondecreasing with respect to s. For
we get
and obviously, 
Hence, for
we have
furthermore,
for we get
and obviously, for
. we get
on the other hand, for 
we have 

and
obviously holds for
For 

and for
we have

Therefore, the proof of Lemma 7 is completed.
Lemma 8. Let
then the Green functions defined by (12) satisfies:
is continuous and
for all 
for all
in which
Proof. The proof is similar to Lemma 3 of [20], we omit it here.
Now we define a cone K on C1[0; 1] and an operator A : K
as follows:

where
and

Problems (1), (2) has a positive solution if and only if u is a fixed point of A in K.
3 Main results
Lemma 9. The operator is continuous.
Proof. First, by the integrability of f and (H0) we get

so we have that A is well defined on K. Moreover, it follows from the uniform continuityof G(t; s) on [0; 1] [0; 1] and (H0)

Thus,
we have that Furthermore, by the uniform continuity of
, we get

Let
Since
are uniformly continous, there exists M>0 such that

On the other hand, since
, there exists A > 0 such that
.and then
Furthermore, by (H0) we have

so, we have
[17]hence, for any
there exists
such, for any 
by (17) and Lebesgue controls convergence theorem, we have
[18]By
for the above
there exists N such that for all n>N, we get
Hence, for any for any hence, for any
by (18) we obtain
[19]Thus, for n>
bye (19) we have

and

and hence, we get
That is,
namely, A is continuous in the space E .
Lemma 10.
is completely continuous.
Proof. From Lemma 7 we have
y

thus, 
consequently,

On the other hand, for all
by Lemma 7 we have

Hence

Thus, 
Now we will prove that AV is relatively compact for bounded
Since V isbounded, there exists
such that for any
,we have

Similarly, for
we derive

which shows that AV is bounded. Next, we will verify that
is equicontinuous. Let
we get

Furthermore,

Thus, we obtain

From above and the uniform continuity of
, and together with Lemma 3, wecan derive that AV is relatively compact in
C1[0; 1], and so we get that
is completely continuous
Let
be nonnegative continuous convex functionals on
be
a nonnegative continuous concave functional on P, and be a nonnegative continuous functional on P. Then for nonnegative numbers e, c, d, h, we define the following convex sets:.

We will apply the following fixed point theorem of Avery and Peterson to solve problem (1), (2).
Let the convex functions
on P, and define a concave function where
are the same as in Lemma 7.
Theorem 1:Assume that there exist positive numbers e,c,d,h with 
and
such that

Then problem (1), (2) has at least three fixed points u1,u2 , u3 satisfying
[20]y
[21]
[22]Proof. Let
. By condition H1 we get


Consequently, we obtain
This together with Lemmas 9 and 10, means that:
completely continuous.
Take
By simple calculation we have 
and so 


which shows that condition (S1) is satisfied.
Take
Since
we obtain

which implies that condition (S2) holds.
Next, we will verify that condition (S3) holds. For
we have
Let
and
by (H3) we get


and

Consequently, we have
Thus, condition (S3) holds.By Lemma 4 we get that (1), (2) has at least three positive solutions u1, u2, u3 satisfying (20)–(22).
4 An example
Consider the following infinite-point p-Laplacian fractional differential equations:

where

Cearly

and

so
is integrable, condition (H0) holds.
We take
by simple calculation we have

Hence, we have

and as
Let
Then for
we for

so condition (H1) of Therem 1 hold. For
by MATLAB software we have

therefore, condition (H2) of Theorem 1 hold. By the same method with proofing (H1) we get (H3) hold, so all the conditions of Theorem 1 hold. Hence, the BVP (23) has at least three positive solutions u1, u2, u3 satisfying 

Acknowledgments
This research was supported by the National Natural Science Foundation of China (12101086, 11871302),Changzhou Science and technology planning project (CJ20210133), and Project of Shandong Province Higher Educational Science and Technology Program (J18KA217)
Bibliography
1 R.I. Avery, J. Henderson, Three positive fixed points of nonlinear operators on ordered Banach spaces, Comput. Math. Appl., 42(3):313–322, 2001, https://doi.org/10.1016/S0898-1221(01)00156-0.
2A. Cabada, Z. Hamdi, Nonlinear fractional differential equations with integral boundary value conditions, Appl. Math. Comput., 228(2012):251–257, 2014, https://doi.org/10.7153/fdc-2019-09-05.
3D. Guo, Y. Cho, J. Zhu, Partial Ordering Methods in Nonlinear Problems, Nova, New York, 2004.
4L. Guo, L. Liu, Unique iterative positive solutions for a singular p-Laplacian fractional differential equation system with infinite-point boundary conditions, Bound. Value Probl., 2019:113, 2019, https://doi.org/10.1186/s13661-019-1227-8. Nonlinear Anal. Model. Control, 27(4):609–629, 2022628 L. Guo et al.
5L. Guo, L. Liu, Y. Feng, Uniqueness of iterative positive solutions for the singular infinite-point p-Laplacian fractional differential system via sequential technique, Nonlinear Anal. Model. Control, 25(5), 2020, https://doi.org/10.15388/namc.2020.25.19277.
6L. Guo, L. Liu, Y. Wang, Maximal and minimal iterative positive solutions for p-Laplacian Hadamard fractional differential equations with the derivative term contained in the nonlinear term, AIMS Math., 6(11):12583–12598, 2021, https://doi.org/10.3934/math. 2021725.
7L. Guo, L. Liu, Y. Wu, Iterative unique positive solutions for singular p-Laplacian fractional differential equation system with several parameters, Nonlinear Anal. Model. Control, 23(2): 182–203, 2018, https://doi.org/10.15388/NA.2018.2.3.
8L. Guo, L. Liu, Y. Wu, Y.M. Zou, Blow-up and global solutions for some parabolic systems under nonlinear boundary conditions, J. Korean Math. Soc., 56(4):1017–1029, 2019, https: //doi.org/org/10.4134/JKMS.j180539.
9P. Hentenryck, R. Bent, E. Upfal, An introduction to the Fractional Calculus and Fractional
10M. Jleli, B. Samet, Existence of positive solutions to an arbitrary order fractional differential equation via a mixed monotone operator method, Nonlinear Anal. Model. Control, 20(3):367–376, 2015, https://doi.org/10.15388/NA.2015.3.4.
11 K.S. Jong, Existence and uniqueness of positive solutions of a kind of multi-point boundary value problems for nonlinear fractional differential equations with p-Laplacian operator, Mediterr. J. Math., 15(3):129, 2018, https://doi.org/10.1007/s00009-018-1155-3.
12K.S. Jong, H.C. Choi, Y.H. Ri, Existence of positive solutions of a class of multi-point boundary value problems for p-Laplacian fractional differential equations with singular source terms, Commun. Nonlinear Sci. Numer. Simul., 72:272–281, 2019, https://doi.org/10.1016/j.cnsns.2018.12.021.
13A.A. Kilbas, H.M. Srivastava, J.J. Trujillo, Theory and Applications of Fractional Differential Equations, North-Holland Math. Stud., Vol. 204, Elsevier, Amsterdam, 2006.
14R.W. Leggett, L.R. Williams, Multiple positive fixed points of nonlinear operators on ordered Banach spaces, Indiana Univ. Math. J., 28(4):673–505, 1979, https://doi.org/10.1016/S0898-1221(01)00156-0.
15D. Ma, Positive solutions of multi-point boundary value problem of fractional differential equation, Arab. J. Math. Sci., 21(2):225–236, 2015, https://doi.org/10.1016/j.ajmsc.2014.11.001.
16I. Podlubny, Fractional Differential Equations, Academic Press, New York, 1999.
17 Y. Wang, L. Liu, X. Zhang, Y. Wu, Positive solutions of an abstract fractional semipositone differential system model for bioprocesses of HIV infection, Appl. Math. Comput., 258(C): 312–324, 2015, https://doi.org/10.1016/j.amc.2015.01.080.
18C. Zhai, L. Wang, Some existence,uniqueness results on positive solutions for a fractional differential equation with infinite-point boundary conditions, Nonlinear Anal. Model. Control, 22(4):566–577, 2017, https://doi.org/10.15388/NA.2017.4.10.
19W. Zhang, W. Liu, Existence of solutions for fractional differential equations with infinite point boundary conditions at resonance, Bound. Value Probl., 2018(1):36, 2018, https://doi.org/10.1186/s13661-018-0954-6. https://www.journals.vu.lt/nonlinear-analysis
20X. Zhang, Positive solutions for a class of singular fractional differential equation with infinitepoint boundary value conditions, Appl. Math. Lett., 39:22–27, 2015, https://doi.org/10.1016/j.aml.2014.08.008.
21X. Zhang, L. Liu, Y. Wu, B. Wiwatanapataphee, The spectral analysis for a singular fractional differential equation with a signed measure, Appl. Math. Comput., 257(C):252–263, 2015, https://doi.org/10.1016/j.amc.2014.12.068.
22X. Zhang, Z. Shao, Q. Zhong, Positive solutions for semipositone (k; n k) conjugate boundary value roblems with singularities on space variables, Appl. Math. Lett., 217(16):50–57, 2017, https://doi.org/10.1016/j.aml.2017.04.007.
23X. Zhang, Q. Zhong, Uniqueness of solution for higher-order fractional differential equations with conjugate type integral conditions, Fract. Calc. Appl. Anal., 20(6):1471–1484, 2017, https://doi.org/10.1515/fca-2017-0077.
24X. Zhang, Q. Zhong, Triple positive solutions for nonlocal fractional differential equations with singularities both on time and space variables, Appl. Math. Lett., 80:12–19, 2018, https://doi.org/10.1016/j.aml.2017.12.022.