Search results for "Radial function"

showing 4 items of 4 documents

The variation of the maximal function of a radial function

2017

We study the problem concerning the variation of the Hardy-Littlewood maximal function in higher dimensions. As the main result, we prove that the variation of the non-centered Hardy-Littlewood maximal function of a radial function is comparable to the variation of the function itself.

Mathematics::Functional Analysis42B25 46E35 26A45maximal functionGeneral Mathematicsta111010102 general mathematicsMathematics::Classical Analysis and ODEsradial functionharmoninen analyysi01 natural sciences010101 applied mathematicsCombinatoricsRadial functionMathematics - Classical Analysis and ODEsClassical Analysis and ODEs (math.CA)FOS: Mathematics46E35Maximal operatorMaximal function0101 mathematicsfunktionaalianalyysi42B25Variation (astronomy)26A45MathematicsArkiv för Matematik
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Bochner-Riesz means of functions in weak-L p

1993

The Bochner-Riesz means of order delta greater-than-or-equal-to 0 for suitable test functions on R(N) are defined via the Fourier transform by (S(R)(delta)f)(xi) = (1 - \xi\2/R2)+(delta)f(xi). We show that the means of the critical index delta = N/P - N + 1/2, 1 + infinity, to f(x) in norm and for almost every x in R(N). We also observe that the means of the function absolute value of x-N/p, which belongs to L(p,infinity) (R(N)) but not to the closure of test functions, converge for no x

General MathematicsMathematical analysisFourier-Hankel expansionweak-$L\sp p$test functionBochner-Riesz meanradial functionCombinatoricssymbols.namesakeFourier transformLorentz spacesNorm (mathematics)Fourier transformsymbolsCritical indexFourier-Bessel expansionMAT/05 - ANALISI MATEMATICAMathematicsMonatshefte f�r Mathematik
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Scattering of Particles by Potentials

2013

The three prototypes of spectra of self-adjoint operators, the discrete spectrum, with or without degeneracy, the continuous spectrum, and the mixed spectrum, as well as the corresponding wave functions, contain important information about the physical systems that they describe

PhysicsRadial functionScatteringQuantum mechanicsContinuous spectrumYukawa potentialBorn approximationWave functionDegeneracy (mathematics)Spectral line
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The Variation of the Fractional Maximal Function of a Radial Function

2017

Abstract In this article, we study the regularity of the non-centered fractional maximal operator $M_{\beta}$. As the main result, we prove that there exists $C(n,\beta)$ such that if $q=n/(n-\beta)$ and $f$ is radial function, then $\|DM_{\beta}f\|_{L^{q}({\mathbb{R}^n})}\leq C(n,\beta)\|Df\|_{L^{1}({\mathbb{R}^n})}$. The corresponding result was previously known only if $n=1$ or $\beta=0$. Our proofs are almost free from one-dimensional arguments. Therefore, we believe that the new approach may be very useful when trying to extend the result for all $f\in W^{1,1}({\mathbb{R}^n})$.

CombinatoricsRadial functionGeneral Mathematics010102 general mathematicsMaximal operatorBeta (velocity)Maximal function0101 mathematics01 natural sciencesMathematicsInternational Mathematics Research Notices
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