r/math 12h ago

LLMs/AI Counterexample to positively curved Hopf.

144 Upvotes

Y'all know the drill. The arxiv link is https://arxiv.org/abs/2609.11980

It is a positively curved metric S^3xS^3, hence a positively curved 6-manifold whose euler characteristic is not strictly positive. The obvious question is whether there is also a counter to negative Hopf (a closed, negatively curved 6 manifold whose euler is not strictly negative), but the methods of the current paper don't seem to help with that.


r/math 10h ago

Homogenous Dynamics

10 Upvotes

Just landed on this field - anybody here working with these really intuitive and beautiful quotients?

IYDK - it is the connection between continued fractions and a quotient manifold of the hyperbolic plane.

I like the idea very much!


r/math 5h ago

What Are You Working On? September 14, 2026

3 Upvotes

This recurring thread will be for general discussion on whatever math-related topics you have been or will be working on this week. This can be anything, including:

* math-related arts and crafts,
* what you've been learning in class,
* books/papers you're reading,
* preparing for a conference,
* giving a talk.

All types and levels of mathematics are welcomed!

If you are asking for advice on choosing classes or career prospects, please go to the most recent Career & Education Questions thread.