ABC conjecture and its exceptional-set problem

For every ε>0\varepsilon>0, there are only finitely many triples (a,b,c)Z>03(a,b,c)\in\mathbb{Z}_{>0}^3 such that a+b=ca+b=c, gcd(a,b,c)=1\gcd(a,b,c)=1, and c>rad(abc)1+εc>\operatorname{rad}(abc)^{1+\varepsilon}, where rad(n)=pnp\operatorname{rad}(n)=\prod_{p\mid n}p. Equivalently, the exceptional set of primitive triples violating this inequality is finite for each fixed ε>0\varepsilon>0.

Sources & referencesView supporting material

Primary source

arXiv

Additional references

Progress summary

Refreshed
Partially solved

A new preprint claims infinitely many counterexamples to the ABC inequality, but no independent verification has appeared and the conjecture remains open.

The exceptional-set problem asks whether triples violating the ABC inequality can occur infinitely often. A lone-author preprint dated August 17, 2026 claims that, for fixed small ε>0\varepsilon>0, infinitely many coprime triples satisfy a+b=ca+b=c and c>rad(abc)1+εc>\operatorname{rad}(abc)^{1+\varepsilon}, which would contradict the standard ABC conjecture.

Known results

  • Browning, Lichtman, and Teräväinen, 2024: Nλ(X)=O(X33/50)N_\lambda(X)=O(X^{33/50}) for fixed λ(0,1.001)\lambda\in(0,1.001), improving the earlier O(X2/3)O(X^{2/3}) scale near λ=1\lambda=1.
  • 2025 work: Nλ(X)X(23λ+3)/40+εN_\lambda(X)\ll X^{(23\lambda+3)/40+\varepsilon} for λ(0,2)\lambda\in(0,2), giving N1(X)X0.65+εN_1(X)\ll X^{0.65+\varepsilon}.
  • Mochizuki’s claimed proof of the ABC conjecture remains unaccepted; Scholze and Stix reported a serious gap.

August 2026 claimed infinite exceptional set

N. A. Carella’s preprint states that the counting function of such exceptional triples tends to infinity. This is a claim, not a verified or refereed result; no corroborating proof, objection report, withdrawal, or retraction was found.

Current status (as of August 2026): The ABC conjecture and the claimed infinite-exceptional-set result remain unverified; only substantial upper bounds on the number of potential exceptions are established.

Sources

Solutions 0

No solutions have been posted yet.