Abstract
We define covering and separation numbers for functions. We investigate their properties, and show that for some classes of functions there is exact equality between separation and covering numbers. We provide analogues for various geometric inequalities on covering numbers, such as volume bounds, bounds connected with Hadwiger’s conjecture, and inequalities about M-positions for geometric log-concave functions. In particular we get strong versions of M-positions for geometric log-concave functions.
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Alonso-Gutiérrez, D., Merino, B.González, Jiménez, C.H., Villa, R.: Rogers-Shephard inequality for log-concave functions. J. Funct. Anal. 271(11), 3269–3299 (2016)
Artstein-Avidan, S., Giannopoulos, A., Milman, V.D.: Asymptotic geometric analysis. Part I, Mathematical Surveys and Monographs, vol. 202, American Mathematical Society, Providence, RI (2015)
Artstein-Avidan, S., Klartag, B., Milman, V.: The Santaló point of a function, and a functional form of the Santaló inequality. Mathematika 5(1), 33–48 (2004)
Artstein-Avidan, S., Milman, V.: A characterization of the support map. Adv. Math. 223(1), 379–391 (2010)
Artstein-Avidan, S., Milman, V.: Hidden structures in the class of convex functions and a new duality transform. J. Eur. Math. Soc. 13(4), 975–1004 (2011)
Artstein-Avidan, S., Raz, O.: Weighted covering numbers of convex sets. Adv. Math. 227(1), 730–744 (2011)
Artstein-Avidan, S., Slomka, B.A.: On weighted covering numbers and the Levi-Hadwiger conjecture. Israel J. Math. 209(1), 125–155 (2015)
Ball, K.M.: PhD dissertation, Cambridge
Barvinok, A.: A course in convexity, Graduate Studies in Mathematics, vol. 54, American Mathematical Society, Providence, RI (2002)
Bobkov, S., Madiman, M.: Reverse brunn-minkowski and reverse entropy power inequalities for convex measures. J. Funct. Anal. 262(7), 3309–3339 (2012)
Bourgain, J., Milman, V.: New volume ratio properties for convex symmetric bodies in \({{\bf R}}^n\). Invent. Math. 88(2), 319–340 (1987)
Fradelizi, M., Meyer, M.: Increasing functions and inverse Santaló inequality for unconditional functions. Positivity 12(3), 407–420 (2008)
Gohberg, I., Markus, A.: A problem on covering of convex figures by similar figures (in Russian). Izv. Mold. Fil. Akad. Nauk SSSR 10(76), 87–90 (1960)
Hadwiger, H.: Ungelöstes Probleme Nr. 20. Elem. Math. 12(6), 121 (1957)
Klartag, B., Milman, V.D.: Geometry of log-concave functions and measures. Geom. Dedicata 112(1), 169–182 (2005)
König, H., Milman, V.D.: On the covering numbers of convex bodies, Geometrical Aspects of Functional Analysis (Joram Lindenstrauss and Vitali D. Milman, eds.), Lecture Notes in Mathematics, vol. 1267, Springer, Berlin, 1987, pp. 82–95 (English)
Levi, F.W.: Überdeckung eines Eibereiches durch Parallelverschiebung seines offenen Kerns. Arch. Math. (Basel) 6, 369–370 (1955)
Milman, V.D.: Inégalité de Brunn-Minkowski inverse et applications à la théorie locale des espaces normés. C. R. Acad. Sci. Paris Sér. I Math. 302(1), 25–28 (1986)
Milman, V.D.: Isomorphic symmetrizations and geometric inequalities, Geometric aspects of functional analysis (1986/87), Lecture Notes in Math., vol. 1317, Springer, Berlin, pp. 107–131 (1988)
Milman, V.D.: Geometrization of probability, Geometry and dynamics of groups and spaces, Progr. Math., vol. 265, Birkhäuser, Basel, pp. 647–667 (2008)
Milman, V.D., Pajor, A.: Entropy and asymptotic geometry of non-symmetric convex bodies. Adv. Math. 152(2), 314–335 (2000)
Naszódi, M.: Fractional illumination of convex bodies. Contrib. Discret. Math. 4(2), 83–88 (2009)
Pietsch, A.: Theorie der Operatorenideale (Zusammenfassung), Friedrich-Schiller-Universität, Jena, 1972, Wissenschaftliche Beiträge der Friedrich-Schiller-Universität Jena
Slomka, B.A.: Covering numbers of log-concave functions and related inequalities, Preprint
Acknowledgements
We thank Daniel Rosen for his valuable remarks for fruitful discussions. We also thank the anonymous referees for helpful remarks. This publication is a part of a project that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No. 770127). The first named author was supported by ISF Grant Number 665/15.
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Artstein-Avidan, S., Slomka, B.A. Functional Covering Numbers. J Geom Anal 31, 1039–1072 (2021). https://doi.org/10.1007/s12220-019-00310-3
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DOI: https://doi.org/10.1007/s12220-019-00310-3