We prove an equiconvergence theorem for Laguerre expansions with partial sums related to partial sums of the (non-modified) Hankel transform. Combined with an equiconvergence theorem recently proved by Colzani, Crespi, Travaglini and Vignati this gives, via the Carleson-Hunt theorem, a.e. convergence results for partial sums of Laguerre function expansions.

Here we prove results about Riesz summability of classical Laguerre series, locally uniformly or on the Lebesgue set of the function f such that (∫(1 + x)^(mp) |f(x)|^p dx )^(1/p) < ∞, for some p and m satisfying 1 ≤ p ≤ ∞, −∞ < m < ∞.

We consider Boolean functions defined on the discrete cube $-\gamma ,{\gamma }^{-1}ⁿ$ equipped with a product probability measure ${\mu }^{\otimes n}$, where $\mu =\beta {\delta }_{-\gamma }+\alpha {\delta }_{{\gamma }^{-1}}$ and γ = √(α/β). This normalization ensures that the coordinate functions ${\left(x_i\right)}_{i=1,...,n}$ are orthonormal in $L₂(-\gamma ,{\gamma }^{-1}ⁿ,{\mu }^{\otimes n})$. We prove that if the spectrum of a Boolean function is concentrated on the first two Fourier levels, then the function is close to a certain function of one variable. Our theorem strengthens the non-symmetric FKN Theorem due to Jendrej, Oleszkiewicz and Wojtaszczyk. Moreover, in the symmetric...

We show that the Fourier-Laplace series of a distribution on the real, complex or quarternionic projective space is uniformly Cesàro-summable to zero on a neighbourhood of a point if and only if this point does not belong to the support of the distribution.

By a general Franklin system corresponding to a dense sequence of knots 𝓣 = (tₙ, n ≥ 0) in [0,1] we mean a sequence of orthonormal piecewise linear functions with knots 𝓣, that is, the nth function of the system has knots t₀, ..., tₙ. The main result of this paper is a characterization of sequences 𝓣 for which the corresponding general Franklin system is a basis or an unconditional basis in H¹[0,1].

Let ${ℳ}_p={m_k}_{k=0}^{p-1}$ be a finite set of step functions or real valued trigonometric polynomials on = [0,1) satisfying a certain orthonormality condition. We study multiscale generalized Riesz product measures μ defined as weak-* limits of elements ${\mu }_N\in V_N\left(N\in \mathbb{N}\right)$, where $V_N$ are $p^N$-dimensional subspaces of L₂() spanned by an orthonormal set which is produced from dilations and multiplications of elements of ${ℳ}_p$ and $\overline{{\bigcup }_{N\in \mathbb{N}}{V}_N}=L₂\left(\right)$. The results involve mutual absolute continuity or singularity of such Riesz products extending previous results on...

Connections between Hankel transforms of different order for $L^p$-functions are examined. Well known are the results of Guy [Guy] and Schindler [Sch]. Further relations result from projection formulae for Bessel functions of different order. Consequences for Hankel multipliers are exhibited and implications for radial Fourier multipliers on Euclidean spaces of different dimensions indicated.

Our main result is a Hardy type inequality with respect to the two-parameter Vilenkin system (*) $({\sum }_{k=1}^{\infty }{\sum }_{j=1}^{\infty }{\left|f̂(k,j)\right|}^p{\left(kj\right)}^{p-2}{)}^{1/p}\le C_p\parallel f{\parallel }_{H_{**}^p}$ (1/2 < p≤2) where f belongs to the Hardy space $H_{**}^p\left(G_m\times G_s\right)$ defined by means of a maximal function. This inequality is extended to p > 2 if the Vilenkin-Fourier coefficients of f form a monotone sequence. We show that the converse of (*) also holds for all p > 0 under the monotonicity assumption.