RT info:eu-repo/semantics/article T1 The convolution of two differentiable functions on the circle need not be differentiable A1 Jiménez Rodríguez, Pablo A1 Muñoz Fernández, Gustavo A. A1 Seoane Sepúlveda, Juan A. A1 Sáez Maestro, Eva AB The convolution operator is well-known for preserving the best properties of its parent functions, and is often presented as a “smoothing” operator. In the present result, we construct two differentiable functions whose convolution is not differentiable. YR 2019 FD 2019 LK https://uvadoc.uva.es/handle/10324/83409 UL https://uvadoc.uva.es/handle/10324/83409 LA eng NO Revista Matemática Complutense (2019) 32:187–193 DS UVaDOC RD 06-abr-2026