2024/06/12 by Peter Sjögren, Sjögren, Peter, Maria Vallarino +1
Mathematics · #Advanced Harmonic Analysis Research #Advanced Mathematical Physics Problems #FOS: Mathematics #Functional Analysis (math.FA) #Holomorphic and Operator Theory
paper · pdf · doi:10.48550/arxiv.2406.08032
openalex publication_date 2024/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Let G be the Lie group ℝ2\rtimes ℝ+ endowed with the Riemannian symmetric space structure. Take a distinguished basis X0, X1, X2 of left-invariant vector fields of the Lie algebra of G, and consider the Laplacian Δ=-∑i=02Xi2 and the first-order Riesz transforms \mathcal Ri=XiΔ-1/2, \hskip3pt i=0,1,2. We first show that the atomic Hardy space H1 in G introduced by the authors in a previous paper does not admit a characterization in terms of the Riesz transforms \mathcal Ri. It is also proved that two of these Riesz transforms are bounded from H1 to H1.