We study the "functionalization" of the $ L_p $-projection body and two related important inequalities in geometry. On the class of $ s $-concave functions, a general function counterpart of the $ L_p $-projection body is introduced. In addition, the $ L_p $-Petty projection inequality and the $ L_p $ isoperimetric inequality are established on this class. Finally, we show that the $ L_p $-Petty projection inequality strengthens the $ L_p $ isoperimetric inequality on the same class.
Citation: Tian Gao, Dan Ma. The $ L_p $-Petty projection inequality for $ s $-concave functions[J]. AIMS Mathematics, 2025, 10(4): 7706-7716. doi: 10.3934/math.2025353
We study the "functionalization" of the $ L_p $-projection body and two related important inequalities in geometry. On the class of $ s $-concave functions, a general function counterpart of the $ L_p $-projection body is introduced. In addition, the $ L_p $-Petty projection inequality and the $ L_p $ isoperimetric inequality are established on this class. Finally, we show that the $ L_p $-Petty projection inequality strengthens the $ L_p $ isoperimetric inequality on the same class.
| [1] |
S. Artstein-Avidan, B. Klartag, V. Milman, The Santaló point of a function, and a functional form of the Santaló inequality, Mathematika, 51 (2004), 33–48. https://doi.org/10.1112/S0025579300015497 doi: 10.1112/S0025579300015497
|
| [2] |
S. Artstein-Avidan, B. Klartag, C. Schütt, E. Werner, Functional affine-isoperimetry and an inverse logarithmic Sobolev inequality, J. Funct. Anal., 262 (2012), 4181–4204. https://doi.org/10.1016/j.jfa.2012.02.014 doi: 10.1016/j.jfa.2012.02.014
|
| [3] |
S. Artstein-Avidan, V. Milman, The concept of duality for measure projections of convex bodies, J. Funct. Anal., 254 (2008), 2648–2666. https://doi.org/10.1016/j.jfa.2007.11.008 doi: 10.1016/j.jfa.2007.11.008
|
| [4] |
U. Caglar, M. Fradelizi, O. Guédon, J. Lehec, C. Schütt, E. Werner, Functional versions of $L_p$-affine surface area and entropy inequalities, Int. Math. Res. Notices, 2016 (2016), 1223–1250. https://doi.org/10.1093/imrn/rnv151 doi: 10.1093/imrn/rnv151
|
| [5] |
U. Caglar, E. M. Werner, Divergence for $s$-concave and log concave functions, Adv. Math., 257 (2014), 219–247. https://doi.org/10.1016/j.aim.2014.02.013 doi: 10.1016/j.aim.2014.02.013
|
| [6] |
U. Caglar, D. Ye, Affine isoperimetric inequalities in the functional Orlicz-Brunn-Minkowski theory, Adv. Appl. Math., 81 (2016), 78–114. https://doi.org/10.1016/j.aam.2016.06.007 doi: 10.1016/j.aam.2016.06.007
|
| [7] | I. Chavel, Isoperimetric inequalities: Differential geometric and analytic perspectives, In: Cambridge tracts in mathematics, Cambridge: Cambridge University Press, 2001. |
| [8] |
N. Fang, J. Zhou, LYZ ellipsoid and Petty projection body for log-concave functions, Adv. Math., 340 (2018), 914–959. https://doi.org/10.1016/j.aim.2018.10.029 doi: 10.1016/j.aim.2018.10.029
|
| [9] |
N. Fang, J. Zhou, Projection body and isoperimetric inequalities for $s$-concave functions, Chin. Ann. Math. Ser. B, 44 (2023), 465–480. https://doi.org/10.1007/s11401-023-0025-x doi: 10.1007/s11401-023-0025-x
|
| [10] |
G. Ivanov, E. Werner, Geometric representation of classes of concave functions and duality, J. Geom. Anal., 34 (2024), 260. https://doi.org/10.1007/s12220-024-01703-9 doi: 10.1007/s12220-024-01703-9
|
| [11] | E. Lutwak, A general isepiphanic inequality, Proc. Amer. Math. Soc., 90 (1984), 415–421. |
| [12] | E. Lutwak, D. Yang, G. Zhang, $L_p$ affine isoperimetric inequalities, J. Differ. Geom., 56 (2000), 111–132. |
| [13] | E. Lutwak, D. Yang, G. Zhang, On the $L_p$-Minkowski problem, Trans. Amer. Math. Soc., 356 (2004), 4359–4370. |
| [14] |
V. Milman, L. Rotem, Mixed integrals and related inequalities, J. Funct. Anal., 264 (2013), 570–604. https://doi.org/10.1016/j.jfa.2012.10.019 doi: 10.1016/j.jfa.2012.10.019
|
| [15] | R. Osserman, The isoperimetric inequality, Bull. Amer. Math. Soc., 84 (1978), 1182–1238. |
| [16] | A. Rojo, A. Bloch, The principle of least action: History and physics, Cambridge: Cambridge University Press, 2018. https://doi.org/10.1017/9781139021029 |
| [17] | M. Roysdon, S. Xing, On $L_p$-Brunn-Minkowski type and $L_p$-isoperimetric type inequalities for measures, Trans. Amer. Math. Soc., 374 (2021), 5003–5036. |
| [18] | R. Schneider, Convex bodies: The Brunn-Minkowski theory, 2 Eds., Cambridge: Cambridge University Press, 2013. https://doi.org/10.1017/CBO9781139003858 |
| [19] |
T. Wang, The affine Sobolev-Zhang inequality on ${\rm{BV}}(\Bbb R^n)$, Adv. Math., 230 (2012), 2457–2473. https://doi.org/10.1016/j.aim.2012.04.022 doi: 10.1016/j.aim.2012.04.022
|
| [20] |
G. Zhang, Restricted chord projection and affine inequalities, Geom. Dedicata, 39 (1991), 213–222. https://doi.org/10.1007/BF00182294 doi: 10.1007/BF00182294
|
| [21] |
G. Zhang, The affine Sobolev inequality, J. Differential Geom., 53 (1999), 183–202. https://doi.org/10.4310/jdg/1214425451 doi: 10.4310/jdg/1214425451
|