MathsClub Problems, proofs & good company

The Problems

Not schoolwork — the questions that resisted Erdős, Hilbert, and everyone since. The club keeps three shelves: what is still open, what AI recently settled, and what took humanity centuries.

How many colours force a monochromatic triangle? Erdős's fifty-year-old lower-bound challenge, resolved superexponentially by Astra.

Posed by Paul Erdős · 1970 · Ramsey theory · resolved 2026

Are the hyperfinite II₁ factor's matrix approximations unique — must certain groups be visible in their von Neumann algebras? Disproved by OpenAI's Astra model, ending a fifty-year expectation.

Posed by Alain Connes · 1976 · operator algebras · resolved 2026

Are all finitely generated groups approximable by finite ones? OpenAI's Astra model announces a construction proving not — resolving a central question of group theory.

Posed by Benjamin Weiss / Peter M. Neumann era formulations · 1999 · geometric group theory · resolved 2026

Sums of small independent random variables resist concentrating too sharply. A decade-plus-old conjecture, initially proved by ChatGPT — and by two independent teams the same day.

Posed by Uriel Feige · 2010 · probability / theoretical computer science · resolved 2026

Must a finite set of reals grow fast under addition or multiplication? Over the reals: no — a cascade begun by AI's unit-distance breakthrough. Over the integers the conjecture lives on.

Posed by Paul Erdős / Endre Szemerédi · 1983 · additive combinatorics · resolved 2026

Can every bridgeless graph be covered by circuits traversing each edge exactly twice? Yes — with at most eight loops. Settled by GPT-5.6 Sol after fifty years.

Posed by multiple, 1970s · 1970 · graph theory · resolved 2026

If a polynomial self-map of space has everywhere-invertible derivative, must it be globally invertible? False in three variables: a 216-character counterexample ended an 87-year hunt.

Posed by Heinz Otto Keller · 1939 · polynomial mappings / algebraic geometry · resolved 2026

How many pairs of n plane points can sit exactly one unit apart? Erdős guessed his grid was unbeatable. An AI model proved him wrong — the first prominent open problem resolved autonomously by AI.

Posed by Paul Erdős · 1946 · combinatorial geometry · resolved 2026