Preface |
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xiii | |
1 Introduction |
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1 | (26) |
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1.1 The matrizant as a chain of entire J-inner mvf's |
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2 | (2) |
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1.2 Monodromy matrices of regular systems |
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4 | (1) |
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1.3 Canonical integral systems |
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5 | (1) |
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1.4 Singular, right regular and right strongly regular matrizants |
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6 | (2) |
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1.5 Input scattering matrices |
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8 | (1) |
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1.6 Chains of associated pairs of the first kind |
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9 | (2) |
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1.7 The bitangential direct input scattering problem |
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11 | (1) |
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1.8 Bitangential inverse monodromy and inverse scattering problems |
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12 | (1) |
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1.9 The generalized Schur interpolation problem |
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13 | (1) |
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1.10 Identifying matrizants as resolvent matrices when J = Jpq |
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14 | (1) |
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1.11 Input impedance matrices and spectral functions |
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15 | (2) |
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17 | (2) |
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1.13 Bitangential direct and inverse input impedance and spectral problems |
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19 | (2) |
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1.14 Krein extension problems and Dirac systems |
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21 | (2) |
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1.15 Direct and inverse problems for Dirac-Krein systems |
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23 | (2) |
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25 | (2) |
2 Canonical systems and related differential equations |
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27 | (29) |
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2.1 Canonical integral systems |
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27 | (3) |
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2.2 Connections with canonical differential systems |
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30 | (3) |
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2.3 The matrizant and its properties |
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33 | (3) |
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2.4 Regular case: Monodromy matrix |
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36 | (1) |
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2.5 Multiplicative integral formulas for matrizants and monodromy matrices; Potapov's theorems |
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37 | (6) |
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2.6 The Feller-Krein string equation |
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43 | (4) |
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2.7 Differential systems with potential |
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47 | (2) |
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49 | (2) |
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2.9 The Schrodinger equation |
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51 | (2) |
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53 | (3) |
3 Matrix-valued functions in the Nevanlinna class |
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56 | (51) |
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3.1 Preliminaries on the Nevanlinna class Npxq |
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58 | (7) |
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3.2 Linear fractional transformations and Redheffer transformations |
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65 | (4) |
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3.3 The Riesz-Herglotz-Nevanlinna representation |
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69 | (5) |
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3.4 The class E intersection Npxq of entire mvf's in Npxq |
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74 | (3) |
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3.5 The class Πpxq of mvf's in Npxq with pseudocontinuations |
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77 | (2) |
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3.6 Fourier transforms and Paley-Wiener theorems |
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79 | (2) |
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81 | (3) |
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3.8 J contractive, J-inner and entire J-inner mvf's |
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84 | (7) |
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3.9 Associated pairs of the first kind |
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91 | (2) |
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3.10 Singular and right (and left) regular J-inner mvf's |
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93 | (3) |
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3.11 Linear fractional transformations of Spxq into itself |
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96 | (2) |
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3.12 Linear fractional transformations in Cpxp and from Spxp into Cpxp |
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98 | (4) |
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3.13 Associated pairs of the second kind |
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102 | (3) |
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105 | (2) |
4 Interpolation problems, resolvent matrices and de Branges spaces |
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107 | (51) |
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108 | (4) |
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4.2 The generalized Schur interpolation problem |
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112 | (6) |
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4.3 Right and left strongly regular J-inner mvf's |
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118 | (1) |
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4.4 The generalized Carathdodory interpolation problem |
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119 | (5) |
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4.5 Detour on scalar determinate interpolation problems |
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124 | (3) |
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4.6 The reproducing kernel Hilbert space H(U) |
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127 | (8) |
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4.7 de Branges inclusion theorems |
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135 | (2) |
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4.8 A description of H(W) intersection Lm2 |
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137 | (3) |
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4.9 The classes UAR(J) and UDR(J) of A-regular and B-regular J-inner mvf's |
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140 | (3) |
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4.10 de Branges matrices E and de Branges spaces B(E) |
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143 | (5) |
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4.11 A coisometry from H(A) onto B(E) |
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148 | (1) |
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4.12 Formulas for resolvent matrices W element of E intersection U°rsR(jpq) |
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149 | (2) |
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4.13 Formulas for resolvent matrices A element of E intersection U°rsR(Jp) |
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151 | (4) |
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155 | (3) |
5 Chains that are matrizants and chains of associated pairs |
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158 | (20) |
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5.1 Continuous chains of entire J-inner mvf's |
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158 | (4) |
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5.2 Chains that are matrizants |
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162 | (5) |
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5.3 Continuity of chains of associated pairs |
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167 | (3) |
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5.4 Type functions for chains |
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170 | (7) |
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177 | (1) |
6 The bitangential direct input scattering problem |
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178 | (24) |
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6.1 The set Sdscat(dM) of input scattering matrices |
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178 | (3) |
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6.2 Parametrization of Sdscat(dM) in terms of Redheffer transforms |
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181 | (2) |
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6.3 Regular canonical integral systems |
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183 | (1) |
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6.4 Limit balls for input scattering matrices |
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184 | (5) |
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189 | (3) |
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192 | (1) |
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6.7 Regular systems (= full rank) case |
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193 | (1) |
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193 | (2) |
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195 | (1) |
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6.10 A Weyl-Titchmarsh like characterization for input scattering matrices |
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195 | (5) |
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200 | (2) |
7 Bitangential direct input impedance and spectral problems |
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202 | (39) |
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7.1 Input impedance matrices |
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202 | (4) |
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7.2 Limit balls for input impedance matrices |
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206 | (3) |
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7.3 Formulas for the ranks of semiradii of the limit ball |
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209 | (2) |
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7.4 Bounded mass functions and full rank end points |
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211 | (2) |
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213 | (2) |
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7.6 The Weyl-Titchmarsh characterization of the input impedance |
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215 | (4) |
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7.7 Spectral functions for canonical systems |
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219 | (6) |
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7.8 Parametrization of the set (H(A))psf |
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225 | (5) |
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7.9 Parametrization of the set Σdpsf(dM) for regular canonical integral systems |
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230 | (2) |
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7.10 Pseudospectral and spectral functions for singular systems |
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232 | (5) |
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237 | (4) |
8 Inverse monodromy problems |
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241 | (69) |
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8.1 Some simple illustrative examples |
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244 | (3) |
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8.2 Extremal solutions when J = Im |
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247 | (6) |
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8.3 Solutions for U element of UAR(J) when J is not = to ±Im |
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253 | (5) |
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8.4 Connections with the Livsic model of a Volterra node |
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258 | (11) |
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8.5 Conditions for the uniqueness of normalized Hamiltonians |
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269 | (8) |
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8.6 Solutions with symplectic and/or real matrizants |
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277 | (4) |
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8.7 Entire homogeneous resolvent matrices |
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281 | (4) |
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8.8 Solutions with homogeneous matrizants |
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285 | (6) |
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8.9 Extremal solutions for J is not = to ±Im |
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291 | (3) |
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8.10 The unicellular case for J is not = to ±Im |
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294 | (1) |
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8.11 Solutions with symmetric type |
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295 | (4) |
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8.12 The inverse rnonodromy problem for 2 x 2 differential systems |
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299 | (5) |
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8.13 Examples of 2 x 2 Hamiltonians with constant determinant |
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304 | (4) |
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308 | (2) |
9 Bitangential Krein extension problems |
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310 | (45) |
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9.1 Helical extension problems |
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311 | (6) |
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9.2 Bitangential helical extension problems |
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317 | (3) |
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9.3 The Krein accelerant extension problem |
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320 | (8) |
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9.4 Continuous analogs of the Schur extension problem |
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328 | (6) |
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9.5 A bitangential generalization of the Schur extension problem |
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334 | (4) |
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9.6 The Nehari extension problem for mvf's in Wiener class |
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338 | (9) |
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9.7 Continuous analogs of the Schur extension problem for mvf's in the Wiener class |
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347 | (3) |
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9.8 Bitangential Schur extension problems in the Wiener class |
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350 | (4) |
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354 | (1) |
10 Bitangential inverse input scattering problems |
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355 | (17) |
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10.1 Existence and uniqueness of solutions |
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356 | (1) |
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10.2 Formulas for the solution of the inverse input scattering problem |
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357 | (4) |
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10.3 Input scattering matrices in the Wiener class |
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361 | (1) |
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10.4 Examples with diagonal mvf's bt1 and bt2 |
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362 | (9) |
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371 | (1) |
11 Bitangential inverse input impedance and spectral problems |
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372 | (37) |
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11.1 Existence and uniqueness of solutions |
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373 | (2) |
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11.2 Formulas for the solutions |
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375 | (3) |
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11.3 Input impedance matrices in the Wiener class |
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378 | (5) |
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11.4 Examples with diagonal mvf's bt3 and bt4 = Ip |
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383 | (10) |
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11.5 The bitangential inverse spectral problem |
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393 | (3) |
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396 | (10) |
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406 | (3) |
12 Direct and inverse problems for Dirac-Krein systems |
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409 | (41) |
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12.1 Factoring Hamiltonians corresponding to DK-systems |
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411 | (5) |
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12.2 Matrizants of canonical differential systems corresponding to DK-systems |
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416 | (7) |
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12.3 Direct and inverse monodromy problems for DK-systems |
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423 | (1) |
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12.4 Direct and inverse input scattering problems for DK-systems |
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424 | (3) |
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12.5 Direct and inverse input impedance problems for DK-systems |
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427 | (4) |
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12.6 Direct and inverse spectral problems for DK-systems |
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431 | (2) |
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12.7 The Krein algorithms for the inverse input scattering and impedance problems |
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433 | (2) |
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12.8 The left transform TlUl for Ul element of Wl(jpq) |
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435 | (3) |
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12.9 Asymptotic equivalence matrices |
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438 | (1) |
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12.10 Asymptotic scattering matrices (S-matrices) |
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438 | (5) |
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12.11 The inverse asymptotic scattering problem |
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443 | (2) |
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12.12 More on spectral functions of DK-systems |
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445 | (2) |
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12.13 Supplementary notes |
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447 | (3) |
References |
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450 | (15) |
Symbol index |
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465 | (4) |
Index |
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469 | |