Abstract
We prove that if u 1,u 2:(0,∞)×ℝd→(0,∞) are sufficiently well-behaved solutions to certain heat inequalities on ℝd then the function u:(0,∞)×ℝd→(0,∞) given by \(u^{1/p}=u_{1}^{1/p_{1}}*u_{2}^{1/p_{2}}\) also satisfies a heat inequality of a similar type provided \(\frac{1}{p_{1}}+\frac{1}{p_{2}}=1+\frac{1}{p}\) . On iterating, this result leads to an analogous statement concerning n-fold convolutions. As a corollary, we give a direct heat-flow proof of the sharp n-fold Young convolution inequality and its reverse form.
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Ball, K.: Volumes of sections of cubes and related problems. In: Lindenstrauss, J., Milman, V.D. (eds.) Geometric Aspects of Functional Analysis. Springer Lecture Notes in Math., vol. 1376, pp. 251–260. Springer, Berlin (1989)
Barthe, F.: Inégalités de Brascamp–Lieb et convexité. C.R. Acad. Sci. Paris Sér. I Math. 324, 885–888 (1997)
Barthe, F.: On a reverse form of the Brascamp–Lieb inequality. Invent. Math. 134, 355–361 (1998)
Barthe, F.: Optimal Young’s inequality and its converse: a simple proof. Geom. Funct. Anal. 8, 234–242 (1998)
Barthe, F.: The Brunn–Minkowski theorem and related geometric and functional inequalities. In: International Congress of Mathematicians, vol. II, pp. 1529–1546. Eur. Math. Soc., Zürich (2006)
Barthe, F., Cordero-Erausquin, D.: Inverse Brascamp-Lieb inequalities along the heat equation. In: Geometric Aspects of Functional Analysis. Lecture Notes in Math., vol. 1850, pp. 65–71. Springer, Berlin (2004)
Barthe, F., Cordero-Erausquin, D., Maurey, B.: Entropy of spherical marginals and related inequalities. J. Math. Pures Appl. 86, 89–99 (2006)
Barthe, F., Huet, N.: On Gaussian Brunn–Minkowski inequalities. Stud. Math. 191, 283–304 (2009)
Beckner, W.: Inequalities in Fourier analysis on ℝn. Proc. Natl. Acad. Sci. U.S.A. 72, 638–641 (1975)
Beckner, W.: Inequalities in Fourier analysis. Ann. Math. 102, 159–182 (1975)
Bennett, J., Carbery, A., Christ, M., Tao, T.: The Brascamp–Lieb inequalities: finiteness, structure and extremals. Geom. Funct. Anal. 17, 1343–1415 (2007)
Bennett, J., Bez, N., Carbery, A.: Heat-flow monotonicity related to the Hausdorff–Young inequality (submitted)
Borell, C.: The Ehrhard inequality. C.R. Math. Acad. Sci. Paris 337, 663–666 (2003)
Brascamp, H.J., Lieb, E.H.: Best constants in Young’s inequality, its converse, and its generalization to more than three functions. Adv. Math. 20, 151–173 (1976)
Carlen, E.A., Lieb, E.H., Loss, M.: A sharp analog of Young’s inequality on S N and related entropy inequalities. J. Geom. Anal. 14, 487–520 (2004)
Carlen, E.A., Lieb, E.H., Loss, M.: An inequality of Hadamard type for permanents. Methods Appl. Anal. 13, 1–17 (2006)
Leindler, L.: On a certain converse of Hölder’s inequality. Acta Sci. Math. Szeged 33, 217–223 (1972)
Valdimarsson, S.: Optimisers for the Brascamp–Lieb inequality. Isr. J. Math. 168, 253–274 (2008)
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Both authors were supported by EPSRC grant EP/E022340/1.
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Bennett, J., Bez, N. Closure Properties of Solutions to Heat Inequalities. J Geom Anal 19, 584–600 (2009). https://doi.org/10.1007/s12220-009-9070-2
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DOI: https://doi.org/10.1007/s12220-009-9070-2