English

Talagrand's convolution conjecture up to loglog via perturbed reverse heat

Probability 2026-05-04 v2 Discrete Mathematics Functional Analysis

Abstract

We prove that under the heat semigroup (Pτ)(P_\tau) on the Boolean hypercube, any nonnegative function exhibits a uniform tail bound that is better than Markov's inequality. Specifically, for any τ>0\tau > 0, n1n \geq 1, η>e3\eta > e^3, and f:{1,1}nR+f: \{-1,1\}^n \to \mathbb{R}_+ with fdμ>0\int f d\mu > 0, we have \begin{align*} \mathbb{P}_{X \sim \mu}\left( P_\tau f(X) > \eta \int f d\mu \right) \leq c_\tau \frac{ (\log \log \eta)^{\frac32} }{\eta \sqrt{\log \eta}}, \end{align*} where μ\mu is the uniform measure on the Boolean hypercube {1,1}n\{-1,1\}^n and cτc_\tau is a constant that depends only on τ\tau. This result resolves Talagrand's convolution conjecture up to a dimension-free (loglogη)32(\log \log \eta)^{\frac32} factor. Our proof uses the reverse heat process on the Boolean hypercube, a coupling construction with carefully engineered perturbations of jump rates and a time-smoothed anti-concentration estimate.

Cite

@article{arxiv.2511.19374,
  title  = {Talagrand's convolution conjecture up to loglog via perturbed reverse heat},
  author = {Yuansi Chen},
  journal= {arXiv preprint arXiv:2511.19374},
  year   = {2026}
}

Comments

43 pages, fixed a mistake in the previous draft which was kindly pointed out by Joseph Lehec

R2 v1 2026-07-01T07:52:38.556Z