盧鈺松,王五生
(河池學(xué)院數(shù)學(xué)與統(tǒng)計學(xué)院,廣西 宜州 546300)
一類含有p次冪的弱奇異Volterra-Fredholm型迭代積分不等式
盧鈺松,王五生*
(河池學(xué)院數(shù)學(xué)與統(tǒng)計學(xué)院,廣西 宜州 546300)
研究一類含有p次冪的弱奇異Volterra-Fredholm型迭代積分不等式,利用分數(shù)階導(dǎo)數(shù)和分數(shù)階積分的定義和運算法則,給出不等式中未知函數(shù)的估計,并利用所得結(jié)論給出一類Volterra-Fredholm分數(shù)階積分方程解的上界估計.
弱奇異積分不等式;p次冪;分數(shù)階積分方程
而工程實際中需要研究弱奇異微分方程[6],因此許多數(shù)學(xué)工作者又致力于研究奇異積分不等式[7-9].2014年,Zheng[10]研究了Volterra-Fredholm 型奇異積分不等式
受上述工作的啟發(fā),本文擬構(gòu)造一類含有p次冪的弱奇異Volterra-Fredholm型迭代積分不等式
并利用分數(shù)階導(dǎo)數(shù)和分數(shù)階積分的定義[11]和分數(shù)階導(dǎo)數(shù)的運算法則[12],給出不等式中未知函數(shù)的估計.易知,不等式(3)可將不等式(1)推廣成Volterra-Fredholm型弱奇異積分不等式,不等式(2)推廣成具有重積分且含有p次冪的積分不等式.
定義1[11]3791)設(shè)f是連續(xù)函數(shù),則改進的Riemann-Liouvilleα階導(dǎo)數(shù)由下式定義:
2)設(shè)f是連續(xù)函數(shù),則區(qū)間[0,t]上改進的Riemann-Liouvilleα階積分由下式定義:
引理1[12]2507設(shè)f,g是連續(xù)函數(shù),則改進的Riemann-Liouville分數(shù)階導(dǎo)數(shù)的運算法則為
引理2[10]2假設(shè)0<α<1,f是連續(xù)函數(shù),則
在本文中,R表示全體實數(shù),R0表示非負實數(shù),I=[0,T],T是正實數(shù).
定理1 設(shè)k,p是正常數(shù),0<α<1,g1(t),g2(t)∈C(I,R0),
在區(qū)間[k,∞)上關(guān)于z嚴格單調(diào)遞減.若函數(shù)u(t)滿足不等式(3),則有未知函數(shù)u(t)的估計式
其中G-1是G的逆函數(shù).
證明 令v1(t)為不等式(3)的右端,利用定義1中2)可將v1(t)表示為
易知,在區(qū)間[0,T]上v1(t)>0,單調(diào)不減,且u(t)≤v1(t),
求v1(t)的α階導(dǎo)數(shù),并利用引理2和關(guān)系式u(t)≤v1(t),得
由式(11)(12)得
將不等式(13)的兩邊同除以(t),得
再利用引理1中改進的Riemann-Liouville分數(shù)階導(dǎo)數(shù)的運算法則(6),得
將不等式(16)中的t改寫成τ,然后關(guān)于τ對其兩邊求從0到t的α階分數(shù)積分,并利用引理2,得
由x(t)=-(t)及不等式(17)可得
再由u(t)≤v1(t),v1(t)≤v2(t)及不等式(18)得
由式(10),不等式(19)和v1(t)的定義,得
從而,有
將不等式(22)代入不等式(19),得到所求估計式(8).證畢.
利用定理1研究如下分數(shù)階積分方程:
其中x∈C1(I,R),H1∈C(I×R2,R),H2∈C(I×R,R).
推論1 假設(shè)積分方程(23)中的函數(shù)H1,H2滿足下列條件:
其中g(shù)1,g2,α與定理1中相應(yīng)的定義相同.假設(shè)
在區(qū)間[k,+∞)上關(guān)于z嚴格單調(diào)遞減.若x(t)是積分方程(23)的解,則有估計式
其中G-1是G的逆函數(shù).
證明 根據(jù)假設(shè)條件(24),由積分方程(23)得?t∈I,有不等式
由不等式(26)具有不等式(3)的形式,且不等式(26)中的函數(shù)滿足定理1的條件,從而根據(jù)定理1可得積分方程(23)中未知函數(shù)的估計式(25).
[1]GRONWALL T H.Note on the derivatives with respect to a parameter of the solutions of a system of differential equations[J].Ann Math,1919,20(4):292-296.
[2]MA Qinhua,PE ARI J.Estimates on solutions of some new nonlinear retarded Volterra-Fredholm type integral inequalities[J].Nonlinear Anal,2008,69(2):393-407.
[3]王五生,李自尊.含多個非線性項的時滯積分不等式及其應(yīng)用 [J].數(shù)學(xué)進展,2012,41(5):597-604.
[4]AGARWAL R P,DENG Shengfu,ZHANG Weinian.Generalization of a retarded Gronwall-like inequality and its applications[J].Appl Math Comput,2005,165(3):599-612.
[5]ABDELDAIM A,YAKOUT M.On some new integral inequalities of Gronwall-Bellman-Pachpatte type[J].Appl Math Comput,2011,217(20):7887-7899.
[6]嵇紹春,李剛.一類分數(shù)階脈沖微分方程的解 [J].揚州大學(xué)學(xué)報(自然科學(xué)版),2012,15(4):12-15.
[7]MDVE M.A new approach to an analysis of Henry type integral inequalities and their Bihari type versions[J].J Math Anal Appl,1997,214(2):349-366.
[8]MA Qinhua,YANG Enhao.Bounds on solutions to some nonlinear Volterra integral inequalities with weakly singular kernels[J].Ann Differ Equ,2011,27(3):352-360.
[9]ZHENG Bin.(G′/G)-expansion method for solving fractional partial differential equations in the theory of mathematical physics[J].Commun Theor Phys,2012,58(5):623-630.
[10]ZHENG Bin.Explicit bounds derived by some new inequalities and applications in fractional integral equations[J].J Inequal Appl,2014,4:1-12.
[11]JUMARIE G.Table of some basic fractional calculus formulae derived from a modified Riemann-Liouville derivative for non-differentiable functions[J].Appl Math Lett,2009,22(3):378-385.
[12]WU Guocheng,LEE E W M.Fractional variational iteration method and its application[J].Phys Lett A,2010,374(25):2506-2509.
A class of weakly singular Volterra-Fredholm type iterated integral inequality withp-th power
LU Yusong,WANG Wusheng*
(Sch of Math &Stats,Hechi Univ,Yizhou 546300,China)
This paper investigates a class of iterated Volterra-Fredholm type integral inequality withp-th power.Using the definitions and rules of fractional differential and fractional integral,the estimation of the unknown functions is given clearly.The result is used to give the upper bound estimation of the solutions of a class of Volterra-Fredholm type fractional integral equations.
weakly singular integral inequality;p-th power;fractional integral equation
O 175.5
A
1007-824X(2015)04-0037-04
2015-06-12.* 聯(lián)系人,E-mail:wang4896@126.com.
國家自然科學(xué)基金資助項目(11561019,11161018);廣西高等學(xué)??蒲谢鹳Y助項目(KY2015ZD103,KY2015YB257).
盧鈺松,王五生.一類含有p次冪的弱奇異Volterra-Fredholm型迭代積分不等式[J].揚州大學(xué)學(xué)報(自然科學(xué)版),2015,18(4):37-40.
(責任編輯 青 禾)