Fredholm 算子源于积分算子和微分算子, 又联系到指标理论, 因而它是一类非常重要的算子,本文考察了有界 Fredholm算子组成的空间、它的拟基本解,并用它的拟基本解得出了 Fredholm算子紧扰动的性质,接下来首先证明了一个特殊形式的积分算子为指标为 0 的Fredholm 算子,然后用对偶对的概念重新叙述并证明了 Fredholm 二择一定理(这种表述方法比原来的形式更容易推广),然后利用它考察具体的积分算子和积分算子的边值问题。之后,进入到无界Fredholm算子的研究,考察由 Sturm-Liouville 算式生成的最大算子、最小算子、由最小算子通过分离性边值条件延拓得到的自伴延拓算子的Fredholm 谱集,Fredholm 预解集并得到自伴算子的谱分解。 59579
毕业论文关键词 Fredholm 算子 积分算子 紧扰动 Fredholm 谱集 Fredholm 预解集 Sturm-Liouville 算子 谱分解
Title Fredholm Operator and its application
Abstract Fredholm Operator get its name from Fredholm and other mathematicians’s study of Integral Operators and Differential Operators,and it can links to the theory of index ,so it is an important subject.In this Article ,I study the space consist of Fredholm Oprator,The parametrix, Fredholm Alternatives via Dual Pairs, Applications to Integral Equations and Boundary-Value Problems.After that ,I study the maximal operator,minimal operator ,the self-adjoint operator corresponding to Sturm-Liouville differential expression,their Fredholm spectrum ,Fredholm resolvent. Keywords Fredholm Operator Integral Operator Compact Perturbation Fredholm spectrum Fredholm resolvent Sturm-Liouville Operator
Contents
1 Fredholméééfffƒƒƒ555üüü 2
1.1 Fredholm½¬9ƒ5ü 2
1.2 Fredholméf[ƒ) 3
1.3 Fredholméf;6ƒ 4
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2.2 3»©êß⁄>äØK•A^ 7
3 AAA^^^Sturm-LiouvilleéééfffÔÔÔƒƒƒ˛˛˛ 12
3.1 Sturm-LiouvilleéfÃx!é) 12
3.2 FredholmÃ8!Fredholm˝)8 20
4 (((ÿÿÿ 26
1 Fredholméf ƒ 5ü1.1 Fredholm ½¬9ƒ 5ü½¬µX!YèDâÇ5òmßTèX Y k.Ç5éfßÖß çIkÅßK°TèFredholméf"5µPT çIè (T),·Çk (T) =
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(T)èTéfºfòm ëÍ"e° ½nL²µ3k.éfUéfâÍ|§ òm•ßFredholméf|§ f8¥m "P“µïÏL£XßY§ß·Ç½¬F£X,Y§èlX Y §k Fredholméf|§ 8‹ßŸ•X,Y˛èBanachòm"½nµ S 2 F(X; Y )ßK3" > 0¶ T 2 L(X; Y )ÖjjT Sjj < "ûßkT 2 F(X; Y ); (T) = (S)y²µ-N := N(S);R := R(S),ƒk Eéf^ T(u; v) = Tu + v; 8u 2 M; v 2 Q:Ÿ•MßQ˛èX fòmÖ˜vX = N +M;X = R + QKéf^ T : M Q ! XÇ5ÖÎY.e°·Çƒky²^ SèV ߃kd^ S EꙥŸè˜ ßb ^ S(u; v) =0.KkSu + v = 0; u 2 M; v 2 Q;=Su 2 R; v 2 Q,œdv = 0; Su = 0;ddu = 0; v = 0ß^ Sè¸ "源]自{优尔·~论\文}网·www.youerw.com/ ·Ç ejj ^ T ^ Sjjø© ßKéf^ TèèV ßœdßejjT Sjjø© ßKéf^ TèV ßKdß ˜ ·Çå± òm ©)XeµX = T(M) + Qç?ò⁄ß·ÇkµN(T) NØ¢˛ßTu = 0; u 2 M —^ T(u; 0) = 0;œdu = 0; N(T) Nd˛™å µdimN(T) dimN < 1 qœècodimT(M) = dimQ = codimR·Ç¿JN òáfòmP¶ ke° Ü⁄/™µN = N(T) + PKßX = (N(T) + P) +M = N(T) + (P +M),œdT3P +M˛è¸ ß R(T) = T(P) + T(M); dimT(P) = dimP=X = T(P) + T(M) + U;U + R(T) = Xd±˛ ™f·Çå µcodimR = codimT(M) = codimR(T) + dimP;dimN = dimN(T) + dimPd˛™w, codimR(T); dimN(T)ëͲkÅß=TèFredholméf"øÖ (T) = dimN(T) codR(T) = (dimN dimP) (codimR dimP) = dimN codimR = (S)œd½n y"1.2 Fredholméf [ƒ )½nµ-AµX ! Yèk.Ç5éfߟ•X!YèBanachòmßKe° ¸áÿ„¥¬d µ1:éfAèFredholméf2:3k.éfPl; Pr : Y ! X⁄;éfCl : X ! X,Cr : Y ! Y¶ µPlA = I + ClAPr = I + Cr5µŸ•éfpl; pr©O âA Ü[ƒ )⁄m[ƒ )"y²µ1 ) 2 :©O X!Y fòmV⁄WßøÖkµX = N(A) + V; Y = R(A) +W œèAèFredholméfߧ±˛° òm©)¥å±â "-P : X ! N(A) Q : Y ! WÖP!QÎYÖè˜ "½¬k.éfXeµB : R(A) +W ! Xß /™XeµB(u + w) = A 10 u; 8u 2 R(A);w 2 WŸ•A0 : V ! R(A)L´A : X ! Y3‘˛ Åõ" éfA0èÇ5” "qœèBA = I P; AB = I Q:œèP(X)⁄Q(Y )èkÅëòmßéfP!Q;ß-Pr = Pl := B=å"2 ) 1 :éfI +Cl; I +Cr—¥çIè0 Fredholméf"qPlA = I +ClµN(A) N(I + Cl),œdµdimN(A) dimN(I + Cl) < 1, Fredholm算子及其应用:http://www.youerw.com/shuxue/lunwen_64841.html