44 research outputs found
Endpoint results for spherical multipliers on noncompact symmetric spaces
In this paper we prove boundedness results on atomic Hardy type spaces for multipliers of the spherical transform on noncompact symmetric spaces of arbitrary rank. The multipliers we consider satisfy either inhomogeneous or homogeneous Mihlin-H\uf6rmander type conditions. In particular, we are able to treat the case of {strongly singular multipliers} whose convolution kernels are not integrable at infinity. Thus our results apply also to negative and imaginary powers of the Laplacian
Sicilia—silicon carbide detectors for intense luminosity investigations and applications
Silicon carbide (SiC) is a compound semiconductor, which is considered as a possible alternative to silicon for particles and photons detection. Its characteristics make it very promising for the next generation of nuclear and particle physics experiments at high beam luminosity. Silicon Carbide detectors for Intense Luminosity Investigations and Applications (SiCILIA) is a project starting as a collaboration between the Italian National Institute of Nuclear Physics (INFN) and IMM-CNR, aiming at the realization of innovative detection systems based on SiC. In this paper, we discuss the main features of silicon carbide as a material and its potential application in the field of particles and photons detectors, the project structure and the strategies used for the prototype realization, and the first results concerning prototype production and their performance
Riesz means for the eigenfunction expansions for a class of hypo-elliptic differential operators
Analysis of a distinguished Laplacean on solvable Lie groups
We study a class of kernels associated to functions of a distinguished Laplacian on the solvable group AN occurring in the Iwasawa decomposition G = ANK of a noncompact semisimple Lie group G. We determine the maximal ideal space of a commutative subalgebra of L1, which contains the algebra generated by the heat kernel, and we prove that the spectrum of the Laplacian is the same on all Lp spaces, 1 64 p < 1e. When G is complex, we derive a formula that enables us to compute the Lp norm of these kernels in terms of a weighted Lp norm of the corresponding kernels for the Euclidean Laplacian on the tangent space. We also prove that, when G is either rank one or complex, certain Hardy-Littlewood maximal operators, which are naturally associated with these kernels, are weak type (1, 1)