Exponential decay in two-dimensional classical O(n) models

OpenAI

For every integer n≥3 and finite β>0, spin two-point correlations in finite free-boundary nearest-neighbor square-lattice O(n) models with edge strengths in [0,β] obey a uniform A exp(−m|x−y|) bound. Free-boundary limits inherit the decay.

Sources for this record

What was already known

Earlier rigorous results covered high temperature and a large-component regime; the all-temperature spin-decay case remained open.

AI involvement AI-led

OpenAI credits an internal model with the manuscript and formalization. The record does not establish autonomous origin for this particular argument.

The institution credited as author and the release’s internal-model production account support AI-led involvement.

Importance Major

Establishes the stated all-temperature exponential spin-correlation decay for n≥3.

Limitations

The Lean result concerns finite-volume spin correlations. It does not establish a full transfer-operator gap, fixed-boundary claim, Gibbs-state uniqueness or low-temperature asymptotics. No named human mathematical check or explanation is documented.

Technical verification Formal (Lean 4 / mathlib)

The Lean release scope and comparator match the finite free-boundary spin-correlation theorem, and Main.lean states the resulting ExponentialDecay theorem. The infinite-volume limit and full O(4) spectral gap are outside that formalization.

Formal checking

The Lean release scope and comparator match the finite free-boundary spin-correlation theorem, and Main.lean states the resulting ExponentialDecay theorem. The infinite-volume limit and full O(4) spectral gap are outside that formalization.

Checker
Lean 4/mathlib formalization in ClassicalON/Main.lean
Scope
Finite-volume exponential spin-correlation decay for n≥3, bounded nonnegative couplings and free boundary
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

No named human explains the fixed-target/cluster argument or its complete reasoning; Few is the evidence default.

Correction and publication history