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In complex analysis, functional analysis and operator theory, a Bergman space is a function space of holomorphic functions in a domain ''D'' of the complex plane that are sufficiently well-behaved at the boundary that they are absolutely integrable. Specifically, for , the Bergman space is the space of all holomorphic functions in ''D'' for which the p-norm is finite: : The quantity is called the ''norm'' of the function ; it is a true norm if . Thus is the subspace of holomorphic functions that are in the space L''p''(''D''). The Bergman spaces are Banach spaces, which is a consequence of the estimate, valid on compact subsets ''K'' of ''D'': Thus convergence of a sequence of holomorphic functions in implies also compact convergence, and so the limit function is also holomorphic. If , then is a reproducing kernel Hilbert space, whose kernel is given by the Bergman kernel. ==Special cases and generalisations== If the domain is bounded, then the norm is often given by : where is a normalised Lebesgue measure of the complex plane, i.e. The Bergman space is usually defined on the open unit disk of the complex plane, in which case . In the Hilbert space case, given , we have : that is, is isometrically isomorphic to the weighted ''ℓp(1/(n+1))'' space.〔 In particular the polynomials are dense in . Similarly, if , the right (or the upper) complex half-plane, then : where , that is, is isometrically isomorphic to the weighted ''Lp1/t (0,∞)'' space (via the Laplace transform).〔〔 The weighted Bergman space is defined in an analogous way,〔 i.e. : provided that is chosen in such way, that is a Banach space (or a Hilbert space, if ). In case where , by a weighted Bergman space 〔 we mean the space of all analytic functions such that : and similarly on the right half-plane (i.e. ) we have〔 : and this space is isometrically isomorphic, via the Laplace transform, to the space ,〔〔 where :, that is : 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Bergman space」の詳細全文を読む スポンサード リンク
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