Brevig, Ole FredrikOrtega Cerdà, JoaquimSeip, KristianZhao Jing2023-04-212023-04-212018-090208-6573https://hdl.handle.net/2445/197005We state and discuss several interrelated results, conjectures, and questions regarding contractive inequalities for classical $H^p$ spaces of the unit disc. We study both coefficient estimates in terms of weighted $\ell^2$ sums and the Riesz projection viewed as a map from $L^q$ to $H^p$ with $q \geq p$. Some numerical evidence is given that supports our conjectures.16 p.application/pdfeng(c) Adam Mickiewicz University, 2018Espais de HardyAnàlisi harmònicaDesigualtats (Matemàtica)Hardy spacesHarmonic analysisInequalities (Mathematics)info:eu-repo/semantics/article6805772023-04-21info:eu-repo/semantics/openAccess