Results 61 to 70 of about 5,128,390 (250)
An Inverse Function Theorem in Frechet Spaces [PDF]
, 2010 I present an inverse function theorem for differentiable maps between Frechet spaces which contains the classical theorem of Nash and Moser as a particular case. In contrast to the latter, the proof does not rely on the Newton iteration procedure, but on
I. Ekeland
semanticscholar +1 more source
Closed spectral measures in Fréchet spaces
International Journal of Mathematics and Mathematical Sciences, 1984 Closed spectral measures, which are often used in the theory of operators, have the desirable property that their L1-space is complete. In this note criteria are given which assure the closedness of spectral measures acting in Fréchet spaces.
W. Ricker
doaj +1 more source
Validation of machine learning based scenario generators
Journal of Risk and Insurance, EarlyView.Abstract Machine learning (ML) methods are becoming increasingly important for designing economic scenario generators for internal models. Validating data‐driven models requires different methods than validating classical, theory‐based models. We discuss two novel aspects of such validation: first, checking the multivariate distribution of risk factors,
Gero Junike, Solveig Flaig, Ralf Werner
wiley +1 more source
Perfect maps in compact (countably compact) spaces
International Journal of Mathematics and Mathematical Sciences, 1995 In this paper, among other results, characterizations of perfect maps in compact Hausdorff(Fréchet, countably compact, Hausdorff) spaces are obtained.
G. L. Garg, Asha Goel
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Stability of a generalization of the Fréchet functional equation
Annales Universitatis Paedagogicae Cracoviensis: Studia Mathematica, 2015 We prove some stability and hyperstability results for a generalization of the well known Fréchet functional equation, stemming from one of the characterizations of the inner product spaces. As the main tool we use a fixed point theorem for the function
Renata Malejki
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Asymptotic behavior of Fréchet functional equation and some characterizations of inner product spaces [PDF]
, 2023 Choonkil Park +4 more
openalex +1 more source
A Conditional Tail Expectation Type Risk Measure for Time Series
Journal of Time Series Analysis, EarlyView.ABSTRACT We consider the estimation of the conditional expectation 𝔼(Xh|X0>UX(1/p)), provided 𝔼|X0|<∞, at extreme levels, where (Xt)t∈ℤ$$ {\left({X}_t\right)}_{t\in \mathbb{Z}} $$ is a strictly stationary time series, UX$$ {U}_X $$ its tail quantile function, h$$ h $$ is a positive integer and p∈(0,1)$$ p\in \left(0,1\right) $$ is such that p→0$$ p\to ...
Yuri Goegebeur +2 more
wiley +1 more source
Almost automorphic functions with values in p-Frechet spaces
Electronic Journal of Differential Equations, 2008 In this paper we develop a theory of almost automorphic functions with values in p-Frechet spaces ...
Gaston M. N'Guerekata +2 more
doaj
, 2013 We introduce global wave-front sets $\operatorname{WF}_{{\mathcal B}} (f)$, $f\in {\mathscr S}^\prime(\textbf{R}^d)$, with respect to suitable Banach or Fr\'echet spaces ${\mathcal B}$.
Boggiatto +28 more
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Density‐Valued ARMA Models by Spline Mixtures
Journal of Time Series Analysis, EarlyView.ABSTRACT This paper proposes a novel framework for modeling time series of probability density functions by extending autoregressive moving average (ARMA) models to density‐valued data. The method is based on a transformation approach, wherein each density function on a compact domain [0,1]d$$ {\left[0,1\right]}^d $$ is approximated by a B‐spline ...
Yasumasa Matsuda, Rei Iwafuchi
wiley +1 more source