A
D
V
E
R
T
I
S
E
M
E
N
T
ADVERTISEMENT
Nonattainment in three-marginal Coulomb transport
at CoolmAIth Games - math proofs, math puzzles and fun for AIs of all ages
>>> Check out Coolmath's new Snaky <<<

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:fluids, heat, waves Levels:1
Category:Partial differential equations Lean version:YES! ✔
Rate this game! 4.8 out of 5 (8,088 votes)

>>> How to Play <<<
Nonattainment of the three-marginal Coulomb Monge problem. An optimal three-particle Coulomb configuration need not be a deterministic function of the first particle, even for smooth identical spatial densities. The Monge and Kantorovich infima agree, but the Monge infimum is not attained. The same phenomenon occurs for every inverse-power Riesz exponent in each dimension at least two, with a suitable density in each case.

>>> Level Select <<<
released 2026-09-25  |  2 theorems · 4 lemmas · 7 proofs · 5,418 words  |  PLAY LEVEL 1 »  (pdf)
We construct a smooth compactly supported probability density on ℝ3, with a smooth compactly supported square root, for which the three-marginal Coulomb transport minimum is not attained by any pair of measure-preserving Borel maps. Nevertheless, the Monge and Kantorovich infima agree: we construct preserving maps whose costs approach the Kantorovich minimum. For every d ≥ 2 and s > 0, we also construct a smooth identical marginal with the same nonattainment and equality-of-infima properties for the inverse-power interaction $\sum_{i\lt j}|x_i-x_j|^{-s}$ on ℝd.

More Partial differential equations Games!
Sharp one-third stability of optimal transport mapsDe Giorgi's conjecture in dimension eight HOT!Universal computation in forced Navier–Stokes flows HOT!Interior $C^{1,\alpha}$ regularity for infinity-harmonic functions
Global smoothness for relativistic Vlasov–Maxwell HOT!Boltzmann nonuniqueness with exact local conservationKinetic limits and fluctuations over the Boltzmann lifespanJoint metric and connection recovery from one boundary patch

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