2013/06/08 by Alexander Pushnitski, Alexander Volberg, Pushnitski, Alexander +1
Mathematics · #47A40 #47G10 #Advanced Banach Space Theory #Advanced Harmonic Analysis Research #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Holomorphic and Operator Theory #Spectral Theory (math.SP) #math.CA #math.SP #msc:47A40 #msc:47G10
paper · pdf · doi:10.48550/arxiv.1306.1912
14 pages, Latex
arxiv created 2013/06/08 · openalex publication_date 2013/06/08 · arxiv updated 2013/06/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The famous two weights problem consists in characterising all possible pairs of weights such that the Hardy projection is bounded between the corresponding weighted L2 spaces. Koosis' theorem of 1980 gives a way to construct a certain class of pairs of weights. We show that Koosis' theorem is closely related to (in fact, is a direct consequence of) a spectral perturbation model suggested by de Branges in 1962. Further, we show that de Branges' model provides an operator-valued version of Koosis' theorem.