Skip to main content
Log in

Separation bodies: a conceptual dual to floating bodies

  • Published:
Monatshefte für Mathematik Aims and scope Submit manuscript

Abstract

Let K be a convex body in Euclidean space \({\mathbb R}^d\), and let a translation invariant, locally finite Borel measure on the space of hyperplanes in \({{\mathbb {R}}}^d\) be given. For \(\delta \ge 0\), we consider the set of all points x for which the set of hyperplanes separating K and x has measure at most \(\delta \). This defines the separation body of K, with respect to the given measure and the parameter \(\delta \). Separation bodies are meant as conceptual duals to floating bodies, and they are expected to play a role in the investigation of random polytopes generated as intersections of random halfspaces, in a similar way that floating bodies are useful for studying convex hulls of random points. After discussing some elementary properties of separation bodies, we carry out first examples to this effect.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Bárány, I.: Intrinsic volumes and \(f\)-vectors of random polytopes. Math. Ann. 285, 671–699 (1989)

    Article  MathSciNet  Google Scholar 

  2. Bárány, I.: Random polytopes, convex bodies, and approximation. In: Baddeley, A., Bárány, I., Schneider, R., Weil, W. (eds.) Stochastic Geometry. Lecture Notes in Mathematics, pp. 77–118. Springer, Berlin (2007)

    Google Scholar 

  3. Bárány, I.: Random points and lattice points in convex bodies. Bull. Am. Math. Soc. 45, 339–356 (2008)

    Article  MathSciNet  Google Scholar 

  4. Bárány, I., Larman, D.G.: Convex bodies, economic cap coverings, random polytopes. Mathematika 35, 274–291 (1988)

    Article  MathSciNet  Google Scholar 

  5. Bárány, I., Vitale, R.A.: Random convex hulls: floating bodies and expectations. J. Approx. Theory 75, 130–135 (1993)

    Article  MathSciNet  Google Scholar 

  6. Besau, F., Ludwig, M., Werner, E.: Weighted floating bodies and polytopal approximation. Trans. Am. Math. Soc. 370, 7129–7148 (2018)

    Article  MathSciNet  Google Scholar 

  7. Besau, F., Schütt, C., Werner, E.: Flag numbers and floating bodies. Adv. Math. 338, 912–952 (2018)

    Article  MathSciNet  Google Scholar 

  8. Besau, F., Werner, E.: The spherical convex floating body. Adv. Math. 301, 867–901 (2016)

    Article  MathSciNet  Google Scholar 

  9. Besau, F., Werner, E.: The floating body in real space forms. J. Differ. Geom. 110, 187–220 (2018)

    Article  MathSciNet  Google Scholar 

  10. Böröczky, K.J., Schneider, R.: The mean width of circumscribed random polytopes. Canad. Math. Bull. 53, 614–628 (2010)

    Article  MathSciNet  Google Scholar 

  11. Fáry, I., Rédei, L.: Der zentralsymmetrische Kern und die zentralsymmetrische Hülle von konvexen Körpern. Math. Ann. 122, 205–220 (1950)

    Article  MathSciNet  Google Scholar 

  12. Fresen, D.: The floating body and the hyperplane conjecture. Arch. Math. 98, 389–397 (2012)

    Article  MathSciNet  Google Scholar 

  13. Fresen, D.: A multivariate Gnedenko law of large numbers. Ann. Probab. 41, 3051–3080 (2013)

    Article  MathSciNet  Google Scholar 

  14. Hug, D., Schneider, R., Poisson hyperplane processes and approximation of convex bodies. Mathematika (accepted) arXiv:1908.09498v1

  15. Jenkinson, J., Werner, E.: Relative entropies for convex bodies. Trans. Am. Math. Soc. 366, 2889–2906 (2014)

    Article  MathSciNet  Google Scholar 

  16. Kaltenbach, F.J., Asymptotisches Verhalten zufälliger konvexer Polyeder. Doctoral Thesis, Albert-Ludwigs-Universität, Freiburg, 1990

  17. Li, B., Schütt, C., Werner, E.M.: Floating functions. Isr. J. Math. 231, 181–210 (2019)

    Article  MathSciNet  Google Scholar 

  18. Molchanov, I.: Theory of Random Sets. Springer, London (2005)

    MATH  Google Scholar 

  19. Mordhorst, O., Werner, E.M., Duality of floating and illumination bodies. arXiv:1709.02424v1

  20. Mordhorst, O., Werner, E.M., Floating and illumination bodies for polytopes: duality results. Discrete Anal. 2019, Paper No. 11, p. 22

  21. Nagy, S., Schütt, C., Werner, E.: Halfspace depth and floating body. Stat. Surv. 13, 52–118 (2019)

    Article  MathSciNet  Google Scholar 

  22. Schneider, R.: Convex Bodies: The Brunn–Minkowski Theory. Encyclopedia of Mathematics and its Applications, 2nd edn. Cambridge University Press, Cambridge (2014)

  23. Schneider, R., Weil, W.: Stochastic and Integral Geometry. Springer, Berlin (2008)

    Book  Google Scholar 

  24. Schütt, C.: The convex floating body and polyhedral approximation. Isr. J. Math. 73, 65–77 (1991)

    Article  MathSciNet  Google Scholar 

  25. Schütt, C., Floating body, illumination body, and polytopal approximation. Convex Geometric Analysis (Berkeley, CA, 1996; K.M. Ball, V. Milman, eds.), pp. 203–229, Math. Sci. Res. Inst. Publ., 34, Cambridge University Press, Cambridge, 1999

  26. Schütt, C., Best and random approximation of convex bodies by polytopes. Rend. Circ. Mat. Palermo (2) Suppl. 70, part II , 315–334 (2002)

  27. Schütt, C., Werner, E.: The convex floating body. Math. Scand. 66, 275–290 (1990)

    Article  MathSciNet  Google Scholar 

  28. Schütt, C., Werner, E.: The convex floating body of almost polygonal bodies. Geom. Dedicata 44, 169–188 (1992)

    Article  MathSciNet  Google Scholar 

  29. Schütt, C., Werner, E.: Homothetic floating bodies. Geom. Dedicata 49, 335–348 (1994)

    Article  MathSciNet  Google Scholar 

  30. Schütt, C., Werner, E.: Surface bodies and \(p\)-affine surface area. Adv. Math. 187, 98–145 (2004)

    Article  MathSciNet  Google Scholar 

  31. Werner, E.: Illumination bodies and affine surface area. Studia Math. 110, 257–269 (1994)

    Article  MathSciNet  Google Scholar 

  32. Werner, E.: The illumination body of a simplex. Discrete Comput. Geom. 15, 297–306 (1996)

    Article  MathSciNet  Google Scholar 

  33. Werner, E.: A general construction for affine surface areas. Studia Math. 132, 227–238 (1999)

    Article  MathSciNet  Google Scholar 

  34. Werner, E., The \(p\)-affine surface area and geometric interpretations. Rend. Circ. Mat. Palermo (2) Suppl. 70, part II, 367–382 (2002)

  35. Werner, E., Floating bodies and illumination bodies. In: Integral Geometry and Convexity: Proceedings of the International Conference, Wuhan, China, 2004, (Grinberg, E.L., Li, S., Zhang, G., Zhou, J., eds.), pp. 129–140. World Scientific, Hackensack (2006)

  36. Werner, E.: On \(L_p\)-affine surface areas. Indiana Univ. Math. J. 56, 2305–2323 (2007)

    Article  MathSciNet  Google Scholar 

  37. Werner, E., Ye, D.: New \(L_p\) affine isoperimetric inequalities. Adv. Math. 218, 762–780 (2008)

    Article  MathSciNet  Google Scholar 

  38. Werner, E., Ye, D.: Inequalities for mixed \(p\)-affine surface areas. Math. Ann. 347, 703–737 (2010)

    Article  MathSciNet  Google Scholar 

  39. Werner, E., Ye, D.: On the homothety conjecture. Indiana Univ. Math. J. 60, 1–20 (2011)

    Article  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Rolf Schneider.

Additional information

Communicated by Adrian Constantin.

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Schneider, R. Separation bodies: a conceptual dual to floating bodies. Monatsh Math 193, 157–170 (2020). https://doi.org/10.1007/s00605-020-01443-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00605-020-01443-2

Keywords

Mathematics Subject Classification

Navigation