Search results for " Riesz"

showing 9 items of 9 documents

The Riesz Representation Theorem and Extension of Vector Valued Additive Measures

2001

Discrete mathematicsPure mathematicsM. Riesz extension theoremRiesz representation theoremKelvin–Stokes theoremRiesz potentialApplied MathematicsBanach spaceExtension (predicate logic)Characterization (mathematics)AnalysisMathematicsJournal of Mathematical Analysis and Applications
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Quadratic variation of martingales in Riesz spaces

2014

We derive quadratic variation inequalities for discrete-time martingales, sub- and supermartingales in the measure-free setting of Riesz spaces. Our main result is a Riesz space analogue of Austinʼs sample function theorem, on convergence of the quadratic variation processes of martingales http://www.journals.elsevier.com/journal-of-mathematical-analysis-and-applications/ http://dx.doi.org/10.1016/j.jmaa.2013.08.037 National Research Foundation of South Africa (Grant specific unique reference number (UID) 85672) and by GNAMPA of Italy (U 2012/000574 20/07/2012 and U 2012/000388 09/05/2012)

Discrete mathematicsPure mathematicsRiesz potentialRiesz representation theoremApplied MathematicsmartingaleRiesz spaceRiesz spacevector latticeQuadratic variationquadratic variationM. Riesz extension theoremSettore MAT/05 - Analisi MatematicaAustin’s theorem Martingale Measure-free stochastic processes Quadratic variation Riesz space Vector latticemeasure-free stochastic processesAustinʼs theoremMartingale (probability theory)AnalysisMathematics
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Integration of functions ranging in complex Riesz space and some applications in harmonic analysis

2015

The theory of Henstock—Kurzweil integral is generalized to the case of functions ranging in complex Riesz space R and defined on any zero-dimensional compact Abelian group. The constructed integral is used to solve the problem of recovering the R-valued coefficients of series in systems of characters of these groups by using generalized Fourier formulas.

Henstock integralSeries (mathematics)Riesz representation theoremRiesz potentialintegral transformGeneral MathematicsMathematical analysisMathematics::Classical Analysis and ODEsHilbert spacegroup characterRiesz spacezero-dimensional compact Abelian groupcharacterHenstock—Kurzweil integralComplex Riesz space character Henstock integral basis integral transform.Riesz transformsymbols.namesakeFourier transformM. Riesz extension theorembasissymbolsMathematics (all)complex Riesz spaceMathematicsMathematical Notes
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Property (w) under compact or Riesz perturbations

2010

Si studia la permanenza della proprietà (w), una variante del Teorema di Weyl, nel caso che un operatore sia perturbato da un operatore compatto oppure di Riesz

Property (w) Riesz operators
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A Hake-Type Theorem for Integrals with Respect to Abstract Derivation Bases in the Riesz Space Setting

2015

Abstract A Kurzweil-Henstock type integral with respect to an abstract derivation basis in a topological measure space, for Riesz space-valued functions, is studied. A Hake-type theorem is proved for this integral, by using technical properties of Riesz spaces.

Pure mathematicsWeak convergenceRiesz representation theoremRiesz potential(D)-convergenceGeneral MathematicsD-convergenceMathematical analysisMathematics::Classical Analysis and ODEsHilbert spaceRiesz spaceRiesz spaceKurzweil-Henstock integralRiesz space order convergence D-convergence Kurzweil-Henstock integral Hake theoremHake theoremsymbols.namesakeRiesz–Fischer theoremM. Riesz extension theoremorder convergencesymbolsMathematics (all)Riesz–Thorin theoremMathematics
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On non-self-adjoint operators defined by Riesz bases in Hilbert and rigged Hilbert spaces

2018

In this paper we discuss some results on non self-adjoint Hamiltonians with real discrete simple spectrum under the assumption that their eigenvectors form Riesz bases of a certain Hilbert space. Also, we exhibit a generalization of those results to the case of rigged Hilbert spaces, and we also consider the problem of the factorization of the aforementioned Hamiltonians in terms of generalized lowering and raising operators.

Pure mathematicssymbols.namesakeNon self-adjoint Hamiltonians Riesz bases rigged Hilbert spacesSettore MAT/05 - Analisi MatematicaHilbert spacesymbolsSelf-adjoint operatorMathematics
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MR3029186 Reviewed Kuo, Wen-Chi; Vardy, Jessica Joy; Watson, Bruce Alastair Mixingales on Riesz spaces. J. Math. Anal. Appl. 402 (2013), no. 2, 731–7…

2013

Settore MAT/05 - Analisi MatematicaMixingales Riesz spaces
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MR2789279 Aziz, Wadie; Leiva, Hugo; Merentes, Nelson; Rzepka, Beata A representation theorem for φ-bounded variation of functions in the sense of Rie…

2012

The authors consider the class $V_\varphi^R (I^b_a)$ of functions $f:I^b_a =[a_1,b_1]\times [a_2,b_2]\subset \mathbb{R}^2 \to \mathbb{R}$ with bounded $\varphi$-total variation in the sense of Riesz, where $\varphi: [0,+ \infty) \to [0,+ \infty)$ is nondecreasing and continuous with $\varphi(0)=0$ and $\varphi(t) \to +\infty$ as $t \to +\infty$. If we assume that $\varphi$ is also such that $\lim_{t \to +\infty}\frac{\varphi(t)}{t}= +\infty$, then we obtain the main result. Precisely, the authors give a characterization of function of two variables defined on a rectangle $I^b_a$ belonging to $V_\varphi^R (I^b_a)$. Clearly, this result is a generalization of the Riesz Lemma.

Settore MAT/05 - Analisi MatematicaVariation bounded variation Riesz
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MR2664252 Aziz, W.; Leiva, H.; Merentes, N.; Sánchez, J. L. Functions of two variables with bounded φ-variation in the sense of Riesz. J. Math. Appl.…

2011

The authors consider the space $BV_\varphi^R (I^b_a,\mathbb{R})$ of functions $f:I^b_a =[a,b]\times [a,b]\subset \mathbb{R}^2 \to \mathbb{R}$ with a $\varphi$-bounded variation in the sense of Riesz, where $\varphi: [0,+ \infty) \to [0,+ \infty)$ is nondecreasing and continuous with $\varphi(0)=0$ and $\varphi(t) \to +\infty$ as $t \to +\infty$. The authors show that $BV_\varphi^R (I^b_a,\mathbb{R})$ is a Banach algebra. Let $h: I^b_a \times \mathbb{R} \to \mathbb{R}$ and let $H: \mathbb{R}^{I^b_a} \to \mathbb{R}$ be the composition operator associated to $h$, that is the operator defined by $(Hf)(x)= h(x, f(x))$ for each $x \in I^b_a$. Then the authors consider the problem of characterizin…

Settore MAT/05 - Analisi Matematicabounded φ-variation Riesz
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