Results 31 to 40 of about 132 (119)
Mathematics, 2022 Extended Dynamic Mode Decomposition (EDMD) allows an approximation of the Koopman operator to be derived in the form of a truncated (finite dimensional) linear operator in a lifted space of (nonlinear) observable functions.
Camilo Garcia-Tenorio +1 more
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Unbounded Quasinormal Operators Revisited [PDF]
Integral Equations and Operator Theory, 2014 Various characterizations of unbounded closed densely defined operators commuting with the spectral measures of their moduli are established.In particular, Kaufman's definition of an unbounded quasinormal operator is shown to coincide with that given by the third-named author and Szafraniec.
Jabłoński, Zenon +2 more
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On Quasinormal Subgroups II [PDF]
Nagoya Mathematical Journal, 1966 A subgroup was defined by O. Ore to be quasinormal in a group if it permuted with all subgroups of the group, and he proved [5] that such a subgroup is subnormal (= subinvariant = accessible) in a finite group. Finite groups in which all subgroups are quasinormal were classified by K. Iwasawa [3], and more recently N. Ito and J. Szép [2] and the author
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Mr-factors and Qr-factors for near quasinorm on certain sequence spaces
International Journal of Mathematics and Mathematical Sciences, 2005 We study the multiplicativity factor and quadraticity factor for near quasinorm on certain sequence spaces of Maddox, namely, l(p) and l∞(p), where p=(pk) is a bounded sequence of positive real numbers.
Piyapong Niamsup, Yongwimon Lenbury
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On the Rarity of Quasinormal Subgroups
Rendiconti del Seminario Matematico della Università di Padova, 2011 For each prime p and positive integer n , Berger and Gross have defined a finite p
Cossey, Peter (John) +1 more
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Perturbations of Regularized Determinants of Operators in a Banach Space
Journal of Mathematics, 2013 Let be a separable Banach space with the approximation property. For an integer , let be a quasinormed ideal of compact operators in with a quasinorm , such that , where are the eigenvalues of and is a constant independent of . We suggest upper and
Michael Gil
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Subnormality and quasinormality of Toeplitz operators [PDF]
Proceedings of the American Mathematical Society, 1972 Halmos asks whether every subnormal Toeplitz operator on H2 is either analytic or normal. It is shown that for a certain class of Toeplitz operators, the subnormality implies either analyticity or normality.
Ito, Takashi, Tin Kin Wong
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Symmetric Spaces of Measurable Functions: Old and New Advances
Современная математика: Фундаментальные направления, 2020 The article is an extensive review in the theory of symmetric spaces of measurable functions. It contains a number of new (recent) and old (known) results in this field.
M. A. Muratov, B.-Z. A. Rubshtein
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Quasinormal modes prefer supersymmetry? [PDF]
Physical Review D, 2003 3 ...
Ling, Yi, Zhang, Hongbao
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Generalized Lebesgue Points for Hajłasz Functions
Journal of Function Spaces, 2018 Let X be a quasi-Banach function space over a doubling metric measure space P. Denote by αX the generalized upper Boyd index of X.
Toni Heikkinen
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