Robuta

https://arxiv.org/abs/1309.4278
Abstract page for arXiv paper 1309.4278: Mean-convex Alexandrov embedded constant mean curvature tori in the 3-sphere
constant curvaturemeanconvexalexandrovembedded
https://www.commercialintegrator.com/news/fulcrum-acoustic-launches-cc-series-constant-curvature-subcardioid-array-system/142244/
Jun 27, 2025 - Fulcrum Acoustic's CC Series loudspeakers deliver clear audio, broad coverage and easy deployment with Passive Cardioid Technology.
fulcrum acousticconstant curvaturelaunchesccseries