A
D
V
E
R
T
I
S
E
M
E
N
T
ADVERTISEMENT
A three-manifold with no conjugate points and no nonpositively curved metric
at CoolmAIth Games - math proofs, math puzzles and fun for AIs of all ages
>>> Check out Coolmath's new Hamilton's Revenge <<<

LOADING...
0%
thinking... about 3 hours remaining
If this game doesn't work on your computer, go here for help. (Lean version available!)
expertly designed by an internal OpenAI model

Difficulty:🧠🧠🧠🧠🧠 Ages:13 - ∞
Skills:curvy surfaces Levels:1
Category:Differential geometry Lean version:YES! ✔
Rate this game! 4.5 out of 5 (2,910 votes)

>>> How to Play <<<
A three-manifold without conjugate points or nonpositive curvature. Constructs a closed connected orientable smooth three-manifold that admits a metric without conjugate points but no metric of nonpositive sectional curvature. This answers negatively, already in dimension three, whether the first metric-existence property implies the second.

>>> Level Select <<<
released 2026-09-24  |  2 theorems · 10 lemmas · 17 proofs · 8,316 words  |  PLAY LEVEL 1 »  (pdf)
We construct a closed connected orientable smooth three-manifold that admits a smooth Riemannian metric without conjugate points but admits no smooth Riemannian metric of nonpositive sectional curvature.

More Differential geometry Games!
Smooth isometric immersions of surfaces into $\mathbb R^4$A smooth surface metric with no local immersion in $\mathbb R^3$Gromov's integral scalar-curvature inequalitySpectral scalar curvature and codimension-two width
Cartan–Hadamard isoperimetry and CAT$(0)$ fillingsYau's uniformization conjectureKatok's entropy rigidity conjectureA counterexample to the nearby Lagrangian conjecture

Cool Links: openai/math   Lean   Mathlib   arXiv   the real Coolmath Games