preprint Nikolaos Chalmoukis author Stefano Meda author Effie Papageorgiou author Federico Santagati author TRR 358: Ganzzahlige Strukturen in Geometrie und Darstellungstheorie project In this paper we study a variant of the uncentred Hardy--Littlewood maximal operator on Damek--Ricci spaces in which balls are replaced by suitable half balls. Perhaps surprisingly, such modified maximal operator has better boundedness properties than the classical one. In particular, it satisfies an $L\log L$ endpoint estimate and it is bounded on $L^p$ for every $p$ in $(1,\infty]$. 2026 eng 2604.27839 Chalmoukis, Nikolaos, Stefano Meda, Effie Papageorgiou, and Federico Santagati. “Uncentred Maximal Operators with Respect to Half Balls on Damek--Ricci Spaces.” <i>ArXiv:2604.27839</i>, 2026. N. Chalmoukis, S. Meda, E. Papageorgiou, and F. Santagati, “Uncentred maximal operators with respect to half balls on Damek--Ricci spaces,” <i>arXiv:2604.27839</i>. 2026. Chalmoukis N, Meda S, Papageorgiou E, Santagati F. Uncentred maximal operators with respect to half balls on Damek--Ricci spaces. <i>arXiv:260427839</i>. Published online 2026. Chalmoukis, N., Meda, S., Papageorgiou, E., &#38; Santagati, F. (2026). Uncentred maximal operators with respect to half balls on Damek--Ricci spaces. In <i>arXiv:2604.27839</i>. N. Chalmoukis, S. Meda, E. Papageorgiou, F. Santagati, ArXiv:2604.27839 (2026). @article{Chalmoukis_Meda_Papageorgiou_Santagati_2026, title={Uncentred maximal operators with respect to half balls on Damek--Ricci spaces}, journal={arXiv:2604.27839}, author={Chalmoukis, Nikolaos and Meda, Stefano and Papageorgiou, Effie and Santagati, Federico}, year={2026} } Chalmoukis, Nikolaos, et al. “Uncentred Maximal Operators with Respect to Half Balls on Damek--Ricci Spaces.” <i>ArXiv:2604.27839</i>, 2026. 655462026-05-03T19:27:27Z2026-05-03T19:29:33Z