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Kannan-Lovász-Simonovits Conjecture


The Kannan-Lovász-Simonovits conjecture, also called the KLS conjecture, asserts a dimension-independent bound for the Poincaré constant of every isotropic logarithmically concave distribution. Isotropic means that the mean is zero and the covariance matrix is the identity matrix. Its original geometric formulation concerns isoperimetric inequalities in convex bodies (Kannan et al. 1995).

Song and Zhang (2026) and Bizeul et al. (2026) reported proofs that an absolute constant C>0 satisfies C_P(mu)<=C for every isotropic logarithmically concave distribution mu on R^n and every n>=1. For a general full-dimensional logarithmically concave distribution, the equivalent bound is

 ||Cov(mu)||_(op)<=C_P(mu)<=C||Cov(mu)||_(op),

where Cov(mu) is its covariance matrix and ||·||_(op) is the operator norm. Bizeul et al. (2026) identify a criterion of Song and Zhang (2026) as the crucial step in their proof. Bizeul et al. (2026) state that ChatGPT found most proofs and mathematical ideas, with the suspension idea supplied by the authors.

Balasubramanian and Kasiviswanathan (2026) reported a deterministic variational proof of the explicit bound C_P(mu)<=25 for every isotropic logarithmically concave distribution mu, independently of dimension. Balasubramanian and Kasiviswanathan (2026) credit AI with formulating a rank-uniform weighted Hodge comparison and proposing Appell coefficient norms for repeated centered integration.

Zhao (2026) reports a Lean 4 formalization of the bound C_P(mu)<14 for every isotropic logarithmically concave distribution mu, independently of dimension. The development refines the deterministic framework of Balasubramanian and Kasiviswanathan (2026).


See also

Convex Body, Logarithmically Concave Distribution, Poincaré Constant, Poincaré Inequality

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References

Balasubramanian, K. and Kasiviswanathan, S. "A Dimension-Free Bound on the Poincaré Constant of Isotropic Log-Concave Measures." 8 Oct 2026. https://arxiv.org/abs/2610.07728v2.Bizeul, P.; Klartag, B.; and Lehec, J. "Presenting a Proof of the Kannan-Lovász-Simonovits Conjecture." 4 Oct 2026. https://arxiv.org/abs/2610.05474.Kannan, R.; Lovász, L.; and Simonovits, M. "Isoperimetric Problems for Convex Bodies and a Localization Lemma." Disc. Comput. Geom. 13, 541-559, 1995. https://doi.org/10.1007/BF02574061.Song, Z. and Zhang, X. "An O(1) Bound for the KLS Constant." 4 Oct 2026. https://arxiv.org/abs/2610.01447v2.Zhao, H. "Dimension-Free KLS Bounds in Lean: Poincaré Constant 14." Version 3.0.0. Zenodo, Oct. 20, 2026. https://doi.org/10.5281/zenodo.23516248.

Cite this as:

Weisstein, Eric W. "Kannan-Lovász-Simonovits Conjecture." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/Kannan-Lovasz-SimonovitsConjecture.html

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