arXiv subjects
Publications and source records attributed to Bechir Amri.
We study the $L^p$-convergence of Fourier expansions in terms of non-symmetric Heckman-Opdam polynomials of type $A_1$. Using kernel estimates and duality arguments, we prove that the partial sums converge in $ L^p([-\pi,\pi],dm_k)$ for $$2-\frac{1}{k+1} < p < 2+\frac{1}{k}.$$
In this paper, a product formula for the one-dimensional $(k,a)$-generalized Fourier kernel is given for $k\geq0$, $a>0$ and $2k>a-1$, extending the special case when $a=\frac{2}{n}$, $n\in \mathbb{N}$.
In this paper we study boundedness of translation invariant operators in the discrete space $\ell^p(\mathbb{Z}^d)$. In this context a Mikhlin type multiplier theorem is given, yielding boundedness for certain known operators . We also give $\ell^p-\ell^q$ boundedness of a discrete wave equation.
In this paper, we consider the Schrödinger operators $L_k=-Δ_k+V$, where $Δ_k$ is the Dunkl-Laplace operator and $V$ is a non-negative potential on $R^d$. We establish that $L_k $ is essentially self-adjoint on $C_0^\infty$. In particular, we develop a bounded $H^\infty$-calculus on $L^p$ spaces for the Dunkl harmonic oscillator operator.
In this paper, we derive a Laplace-type integral representations for both the generalized Bessel function and the Dunkl kernel associated with the rank-two root system of type B_2. The derivation of the first one elaborates on the integral representation of the generalized Bessel function proved in \cite{Demni} through the modified Bessel function of the first kind. In particular, we recover an expression of the density of the Duistermaat-Heckman measure for the dihedral group of order eight. As to the integral representation of the corresponding Dunkl kernel, it follows from an application of the shift principle to the generalized Bessel function.