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2018 | OriginalPaper | Buchkapitel

2. Preparatory Concepts

verfasst von : Piotr Budzyński, Zenon Jabłoński, Il Bong Jung, Jan Stochel

Erschienen in: Unbounded Weighted Composition Operators in L²-Spaces

Verlag: Springer International Publishing

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Abstract

This chapter introduces some concepts of measure theory that will be useful for studying weighted composition operators (including the Radon-Nikodym derivative h ϕ,w and the conditional expectation \(\mathsf {E}(\cdot \,;\phi ^{-1}(\mathscr A),\mu _w)\); see Sects. 2.1 and 2.4). Weighted composition operators are introduced and initially investigated in Sect. 2.2. Assorted classes of weighted composition operators including classical (unilateral and bilateral) weighted shifts and their adjoints are discussed in Sect. 2.3. The polar decompositions of a weighted composition operator and its adjoint are explicitly described in Sect. 2.5. In Sect. 2.6, characterizations of the quasinormality of weighted composition operators are given (see Theorem 20).

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Fußnoten
1
Because of Lemma 6 and Proposition 10, the rational function appearing on the right-hand side of the equality in (2.14) takes complex values a.e. [μ]. What is important here is that \(\tilde w\) satisfies the equality \(\{\tilde w= 0\} = \{w=0\}\) a.e. [μ].
 
Literatur
5.
Zurück zum Zitat R.B. Ash, Probability and Measure Theory (Harcourt/Academic Press, Burlington, 2000) R.B. Ash, Probability and Measure Theory (Harcourt/Academic Press, Burlington, 2000)
7.
Zurück zum Zitat S. Banach, Théorie des opérations linéaires (French). Monografie Matematyczne I (Polish Scientific Publishers, Warszawa, 1932) S. Banach, Théorie des opérations linéaires (French). Monografie Matematyczne I (Polish Scientific Publishers, Warszawa, 1932)
8.
13.
Zurück zum Zitat P. Billingsley, Probability and Measure, 3rd edn. Wiley Series in Probability and Mathematical Statistics (A Wiley-Interscience Publication, John Wiley & Sons, New York, 1995) P. Billingsley, Probability and Measure, 3rd edn. Wiley Series in Probability and Mathematical Statistics (A Wiley-Interscience Publication, John Wiley & Sons, New York, 1995)
14.
Zurück zum Zitat M.Sh. Birman, M.Z. Solomjak, Spectral Theory of Selfadjoint Operators in Hilbert Space (D. Reidel Publishing, Dordrecht, 1987) M.Sh. Birman, M.Z. Solomjak, Spectral Theory of Selfadjoint Operators in Hilbert Space (D. Reidel Publishing, Dordrecht, 1987)
24.
Zurück zum Zitat P. Budzyński, Z.J. Jabłoński, I.B. Jung, J. Stochel, On unbounded composition operators in L 2-spaces. Ann. Mat. Pur. Appl. 193, 663–688 (2014) P. Budzyński, Z.J. Jabłoński, I.B. Jung, J. Stochel, On unbounded composition operators in L 2-spaces. Ann. Mat. Pur. Appl. 193, 663–688 (2014)
25.
Zurück zum Zitat P. Budzyński, Z.J. Jabłoński, I.B. Jung, J. Stochel, A multiplicative property characterizes quasinormal composition operators in L 2-spaces. J. Math. Anal. Appl. 409, 576–581 (2014)MathSciNetCrossRef P. Budzyński, Z.J. Jabłoński, I.B. Jung, J. Stochel, A multiplicative property characterizes quasinormal composition operators in L 2-spaces. J. Math. Anal. Appl. 409, 576–581 (2014)MathSciNetCrossRef
26.
Zurück zum Zitat P. Budzyński, Z.J. Jabłoński, I.B. Jung, J. Stochel, Unbounded subnormal composition operators in L 2-spaces. J. Funct. Anal. 269, 2110–2164 (2015) P. Budzyński, Z.J. Jabłoński, I.B. Jung, J. Stochel, Unbounded subnormal composition operators in L 2-spaces. J. Funct. Anal. 269, 2110–2164 (2015)
33.
Zurück zum Zitat C. Burnap, I.B. Jung, A. Lambert, Separating partial normality classes with composition operators. J. Oper. Theory 53, 381–397 (2005) C. Burnap, I.B. Jung, A. Lambert, Separating partial normality classes with composition operators. J. Oper. Theory 53, 381–397 (2005)
35.
Zurück zum Zitat J.T. Campbell, W.E. Hornor, Seminormal composition operators. J. Oper. Theory 29, 323–343 (1993) J.T. Campbell, W.E. Hornor, Seminormal composition operators. J. Oper. Theory 29, 323–343 (1993)
38.
Zurück zum Zitat J.T. Campbell, J.E. Jamison, On some classes of weighted composition operators. Glasg. Math. J. 32, 87–94 (1990)MathSciNetCrossRef J.T. Campbell, J.E. Jamison, On some classes of weighted composition operators. Glasg. Math. J. 32, 87–94 (1990)MathSciNetCrossRef
40.
Zurück zum Zitat J.T. Campbell, M. Embry-Wardrop, R.J. Fleming, S.K. Narayan, Normal and quasinormal weighted composition operators. Glasg. Math. J. 33, 275–279 (1991)MathSciNetCrossRef J.T. Campbell, M. Embry-Wardrop, R.J. Fleming, S.K. Narayan, Normal and quasinormal weighted composition operators. Glasg. Math. J. 33, 275–279 (1991)MathSciNetCrossRef
41.
Zurück zum Zitat J.W. Carlson, Hyponormal and quasinormal weighted composition operators on ℓ 2. Rocky Mountain J. Math. 20, 399–407 (1990) J.W. Carlson, Hyponormal and quasinormal weighted composition operators on 2. Rocky Mountain J. Math. 20, 399–407 (1990)
42.
Zurück zum Zitat J.W. Carlson, The spectra and commutants of some weighted composition operators. Trans. Am. Math. Soc. 317, 631–654 (1990)MathSciNetCrossRef J.W. Carlson, The spectra and commutants of some weighted composition operators. Trans. Am. Math. Soc. 317, 631–654 (1990)MathSciNetCrossRef
50.
Zurück zum Zitat M. Chō, T. Yamazaki, Characterizations of p-hyponormal and weak hyponormal weighted composition operators. Acta Sci. Math. (Szeged) 76, 173–181 (2010) M. Chō, T. Yamazaki, Characterizations of p-hyponormal and weak hyponormal weighted composition operators. Acta Sci. Math. (Szeged) 76, 173–181 (2010)
54.
Zurück zum Zitat J.B. Conway, A Course in Functional Analysis. Graduate Texts in Mathematics, vol. 96 (Springer, New York, 1990) J.B. Conway, A Course in Functional Analysis. Graduate Texts in Mathematics, vol. 96 (Springer, New York, 1990)
57.
Zurück zum Zitat R.E. Curto, L.A. Fialkow, Recursively generated weighted shifts and the subnormal completion problem, II. Integr. Equ. Oper. Theory 18, 369–426 (1994) R.E. Curto, L.A. Fialkow, Recursively generated weighted shifts and the subnormal completion problem, II. Integr. Equ. Oper. Theory 18, 369–426 (1994)
59.
Zurück zum Zitat A. Daniluk, J. Stochel, Seminormal composition operators induced by affine transformations. Hokkaido Math. J. 26, 377–404 (1997)MathSciNetCrossRef A. Daniluk, J. Stochel, Seminormal composition operators induced by affine transformations. Hokkaido Math. J. 26, 377–404 (1997)MathSciNetCrossRef
61.
Zurück zum Zitat N. Dunford, J.T. Schwartz, Linear Operators, Part I (Interscience, New York, 1958) N. Dunford, J.T. Schwartz, Linear Operators, Part I (Interscience, New York, 1958)
66.
Zurück zum Zitat M.R. Embry, A. Lambert, Measurable transformations and centered composition operators. Proc. Roy. Irish Acad. Sect. A 90, 165–172 (1990) M.R. Embry, A. Lambert, Measurable transformations and centered composition operators. Proc. Roy. Irish Acad. Sect. A 90, 165–172 (1990)
72.
Zurück zum Zitat J. Fujii, M. Fujii, H. Sasaoka, Y. Watatani, The spectrum of an infinite directed graph. Math. Japon. 36, 607–625 (1991) J. Fujii, M. Fujii, H. Sasaoka, Y. Watatani, The spectrum of an infinite directed graph. Math. Japon. 36, 607–625 (1991)
74.
Zurück zum Zitat R. Gellar, L.J. Wallen, Subnormal weighted shifts and the Halmos-Bram criterion. Proc. Jpn. Acad. 46, 375–378 (1970)MathSciNetCrossRef R. Gellar, L.J. Wallen, Subnormal weighted shifts and the Halmos-Bram criterion. Proc. Jpn. Acad. 46, 375–378 (1970)MathSciNetCrossRef
81.
Zurück zum Zitat D. Harrington, R. Whitley, Seminormal composition operators. J. Oper. Theory 11, 125–135 (1984) D. Harrington, R. Whitley, Seminormal composition operators. J. Oper. Theory 11, 125–135 (1984)
82.
Zurück zum Zitat D. Herrero, Subnormal bilateral weighted shifts, Notas mimeografiadas, 1971 D. Herrero, Subnormal bilateral weighted shifts, Notas mimeografiadas, 1971
84.
Zurück zum Zitat Z.J. Jabłoński, I.B. Jung, J. Stochel, Weighted shifts on directed trees. Mem. Am. Math. Soc. 216(1017), viii+107 (2012)MathSciNetCrossRef Z.J. Jabłoński, I.B. Jung, J. Stochel, Weighted shifts on directed trees. Mem. Am. Math. Soc. 216(1017), viii+107 (2012)MathSciNetCrossRef
85.
Zurück zum Zitat Z.J. Jabłoński, I.B. Jung, J. Stochel, A non-hyponormal operator generating Stieltjes moment sequences. J. Funct. Anal. 262, 3946–3980 (2012)MathSciNetCrossRef Z.J. Jabłoński, I.B. Jung, J. Stochel, A non-hyponormal operator generating Stieltjes moment sequences. J. Funct. Anal. 262, 3946–3980 (2012)MathSciNetCrossRef
92.
Zurück zum Zitat B.O. Koopman, Hamiltonian systems and transformations in Hilbert space. Proc. Natl. Acad. Sci. U. S. A. 17, 315–318 (1931)CrossRef B.O. Koopman, Hamiltonian systems and transformations in Hilbert space. Proc. Natl. Acad. Sci. U. S. A. 17, 315–318 (1931)CrossRef
98.
102.
103.
Zurück zum Zitat W. Mlak, The Schrödinger type couples related to weighted shifts. Univ. Iagel. Acta Math. 27, 297–301 (1988)MathSciNetMATH W. Mlak, The Schrödinger type couples related to weighted shifts. Univ. Iagel. Acta Math. 27, 297–301 (1988)MathSciNetMATH
105.
Zurück zum Zitat N.K. Nikolskii, Treatise on the Shift Operator (Springer, Berlin, 1986)CrossRef N.K. Nikolskii, Treatise on the Shift Operator (Springer, Berlin, 1986)CrossRef
106.
Zurück zum Zitat E. Nordgren, Composition Operators on Hilbert Spaces. Lecture Notes in Mathematics, vol. 693 (Springer, Berlin 1978), pp. 37–63 E. Nordgren, Composition Operators on Hilbert Spaces. Lecture Notes in Mathematics, vol. 693 (Springer, Berlin 1978), pp. 37–63
108.
Zurück zum Zitat S.K. Parrott, Weighted translation operators, Thesis (Ph.D.), University of Michigan, 1965, p. 89 S.K. Parrott, Weighted translation operators, Thesis (Ph.D.), University of Michigan, 1965, p. 89
117.
Zurück zum Zitat W. Rudin, Real and Complex Analysis (McGraw-Hill, New York, 1987)MATH W. Rudin, Real and Complex Analysis (McGraw-Hill, New York, 1987)MATH
121.
Zurück zum Zitat K. Schmüdgen, Unbounded Self-adjoint Operators on Hilbert Space. Graduate Texts in Mathematics, vol. 265 (Springer, Dordrecht, 2012) K. Schmüdgen, Unbounded Self-adjoint Operators on Hilbert Space. Graduate Texts in Mathematics, vol. 265 (Springer, Dordrecht, 2012)
123.
Zurück zum Zitat A.L. Shields, Weighted shift operators and analytic function theory, in Topics in Operator Theory. Mathematical Surveys, vol. 13 (American Mathematical Society, Providence, RI, 1974), pp. 49–128CrossRef A.L. Shields, Weighted shift operators and analytic function theory, in Topics in Operator Theory. Mathematical Surveys, vol. 13 (American Mathematical Society, Providence, RI, 1974), pp. 49–128CrossRef
131.
Zurück zum Zitat R.K. Singh, J.S. Manhas, Composition Operators on Function Spaces (Elsevier Science Publishers B.V., North-Holland, 1993)MATH R.K. Singh, J.S. Manhas, Composition Operators on Function Spaces (Elsevier Science Publishers B.V., North-Holland, 1993)MATH
134.
Zurück zum Zitat J. Stochel, Seminormal composition operators on L 2 spaces induced by matrices. Hokkaido Math. J. 19, 307–324 (1990)MathSciNetCrossRef J. Stochel, Seminormal composition operators on L 2 spaces induced by matrices. Hokkaido Math. J. 19, 307–324 (1990)MathSciNetCrossRef
151.
Zurück zum Zitat J. Weidmann, Linear Operators in Hilbert Spaces (Springer, Berlin, 1980)CrossRef J. Weidmann, Linear Operators in Hilbert Spaces (Springer, Berlin, 1980)CrossRef
152.
Metadaten
Titel
Preparatory Concepts
verfasst von
Piotr Budzyński
Zenon Jabłoński
Il Bong Jung
Jan Stochel
Copyright-Jahr
2018
DOI
https://doi.org/10.1007/978-3-319-74039-3_2

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