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Mateo Carmona (Feb 04 2021 at 06:36):https://grothendieckthemes.zulipchat.com/
Mateo Carmona (Feb 04 2021 at 06:44):I am currently working (in particular for the interest of the category theory community) on a transcription of H X Sinh’s thesis -catégories (via link).
Mateo Carmona (Feb 04 2021 at 06:45):You are all welcome @Joshua Meyers @Joe Moeller @Tim Hosgood
Notification Bot (Feb 04 2021 at 09:40):This topic was moved here from #general: off-topic > grothendieck by Matteo Capucci (he/him)
Joshua Meyers (Feb 04 2021 at 10:52):@Mateo Carmona it says I need an invitation?
Mateo Carmona (Feb 04 2021 at 13:06):https://grothendieckthemes.zulipchat.com/join/geazb4z54sj3oknxdqccs6ua/
John Baez (Feb 04 2021 at 16:25):It may be worth mentioning that Hoàng Xuân Sính , often called "Madame Sinh" in the literature, was a Vietnamese student of Grothendieck who in her thesis studied what we now call 2-groups (monoidal categories where all objects and morphisms are invertible). She called them Gr-categories, and she classified them in terms of group cohomology.
She showed that any Gr-category gives an element of where is the group of isomorphism classes of objects and is the group of endomorphisms of the unit object. This is sometimes called the Sinh invariant. It comes from the associator, which gives a 3-cocycle thanks to the pentagon identity. Replacing the Gr-category by a monoidally equivalent one changes this 3-cocycle by a cohomologous one, so the Sinh invariant is a cohomology class.
The Wikipedia article on her calls Hoàng Xuân Sính "the first female mathematician in Vietnam". I don't know how certain that is, but her story is certainly interesting:
The French mathematician and pacifist Alexander Grothendieck visited North Vietnam in late 1967, during the Vietnam War, and spent a month teaching mathematics to the Hanoi University mathematics department staff, including Hoàng, who took the notes for the lectures. Because of the war, Grothendieck's lectures were held away from Hanoi, first in the nearby countryside and later in Đại Từ. After Grothendieck returned to France, he continued to teach Hoàng as a correspondence student. She earned her doctorate under Grothendieck's supervision from Paris Diderot University in 1975, with a handwritten thesis. Her thesis research, on algebraic structures based on categorical groups but with a group law that holds only up to isomorphism, prefigured much of the modern theory of 2-groups.
John Baez (Feb 04 2021 at 16:29):Handwritten thesis! :thumbs_up:
John Baez (Feb 04 2021 at 16:33):When she was promoted to full professor Hoàng became the first female full professor in Vietnam in any scientific or technical field. In 1988 she founded the first private university in Vietnam, Thang Long University in Hanoi, and became the president of its board of directors.
In 2003 she was awarded France's Ordre des Palmes Académiques for her "contributions to boosting cooperation in culture and science between the two nations" of France and Vietnam.
John Baez (Feb 04 2021 at 16:35):She is still alive, apparently! She would be 88 now. I should have contacted her back when I was working on 2-groups!
Jade Master (Jun 28 2021 at 23:25):This looks great and I'd love to take a look but the link seems to be broken.
Mateo Carmona (Jul 06 2021 at 19:16):You can take a look at the Thèmes pour une harmonie section Picard-Brauer or email me at carmonamateogm@gmail.com if you want to contribute to it.
Jade Master (Jul 07 2021 at 17:32):Thank you.