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Functional strong slicing conjecture (three variants) for log-concave functions

Determine the sharp upper bounds of the following isotropic constants for integrable log-concave functions f: ℝ^n → ℝ_+: (i) L_f = [max_x f(x) / ∫ f]^{1/n}·(det Cov(f))^{1/(2n)} is maximized by f_0(x) = exp(−∑_{i=1}^n x_i)·1_{[-1,+∞)^n}(x) with value 1; (ii) L̃_f = [ (∫ f)/f(0) ]^{1/n}·(det Cov(f))^{1/(2n)} is maximized by f_1(x) = exp(−∑_{i=1}^n |x_i| ); (iii) L̂_f = e^{−h(f)}·(∫ f)^{1/n}·(det Cov(f))^{1/(2n)} is maximized by f_0(x) with value 1/e.

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Background

The authors introduce three natural definitions of an isotropic constant for log-concave functions, differing by the use of max f, f(0), or differential entropy h(f). They conjecture the extremizers and maximal values for each, identifying specific candidate functions f_0 and f_1.

These functional strong slicing conjectures aim to mirror the geometric strong slicing conjectures and, in particular, the entropy-based version (iii) is pivotal for deriving functional Mahler’s conjecture via their main theorem.

References

Conjecture 3. Let f : R™ -> R+ be an integrable log-concave function, and fo, f1, f. : Rn -> R+ be the functions given by fo(x) = e-Li=iTix[-1.+co)n (x), fi(x) =e-Li=ilzil and f(x) =X[-1,1]n (x). Then i) Lf ≤ Lf0 = 1, ii) ç§Ã ¡= "}, iii) Lf ≤Îfo=e-1.

Entropy, slicing problem and functional Mahler's conjecture (2406.07406 - Fradelizi et al., 11 Jun 2024) in Section 3 (On the functional isotropic constant), Conjecture 3