The Brazilians Singularity Theory Webinar of this semester will be dedicated to the memory of Maria Aparecida Soares Ruas (Cidinha). Her trajectory deeply marked the development of Singularity Theory in Brazil and worldwide, training generations of mathematicians and consolidating research groups that today continue her legacy.
This special series will feature talks by her collaborators, who will present results and perspectives related to her contributions, celebrating the strength and vitality of her work.
Oct 14th, 2025
Speaker: Alexandre Fernandes - Universidade Federal do Ceará - Brazil
Abstract: This talk is dedicated to Prof. Maria Ruas (Prof. Cidinha), who initiated and developed, with great insight, a project on the rigidity of right bi-Lipschitz equivalence of function-germs. I will present joint work with Prof. Cidinha on the case of weighted homogeneous (but not homogeneous) function-germs in the plane. The main result shows that if two such germs are bi-Lipschitz equivalent—meaning they can be included in a strongly bi-Lipschitz trivial family of weighted homogeneous function-germs—then they are, in fact, analytically equivalent. I will also discuss a follow-up to this result, developed in collaboration with Prof. Leonardo Câmara.
Oct 28th, 2025
Speaker: Hellen Santana - Universidade Federal de São Carlos - Brazil
Abstract: TBA
Nov 11th, 2025
Speaker: Otoniel Silva - Universidade Federal da Paraíba - Brazil
Abstract: TBA
Nov 25th, 2025
Speaker: Nivaldo Grulha - ICMC - Universidade de São Paulo - Brazil
Abstract: TBA