Abstract
The structure of low dimensional sections and projections of symmetric convex bodies is studied. For a symmetric convex bodyB ⊂ ℝn, inequalities between the smallest diameter of rank ℓ projections ofB and the largest in-radius ofm-dimensional sections ofB are established, for a wide range of sub-proportional dimensions. As an application it is shown that every bodyB in (isomorphic) ℓ-position admits a well-bounded (√n, 1)-mixing operator.
Similar content being viewed by others
References
J. Bourgain and S. J. Szarek,The Banach-Mazur distance to the cube and the Dvoretzky-Rogers factorization, Israel Journal of Mathematics62 (1988), 169–180.
J. Bourgain and L. Tzafriri,Invertibility of “large” submatrices with applications to the geometry of Banach spaces and harmonic analysis, Israel Journal of Mathematics57 (1987), 137–224.
E. D. Gluskin,Finite-dimensional analogues of spaces without basis, Doklady Akademii Nauk SSSR216 (1981), 1046–1050.
A. Giannopoulos, V. D. Milman and A. Tsolomitis,Asymptotic formulas for the diameter of sections of symmetric convex bodies, Journal of Functional Analysis223 (2005), 86–108.
P. Mankiewicz,Finite-dimensional Banach spaces with symmetry constant of order √n, Studia Mathematica79 (1984), 193–200.
P. Mankiewicz,Subspace mixing properties of operators in ℝn,with applications to Gluskin spaces, Studia Mathematica88 (1988), 51–67.
P. Mankiewicz and N. Tomczak-Jaegermann,Quotients of finite-dimensional Banach spaces; random phenomena, inHandbook of the Geometry of Banach Spaces (W. B. Johnson and J. Lindenstrauss, eds.), Vol. II, Elsevier, Amsterdam, 2003, pp. 1201–1246.
P. Mankiewicz and N. Tomczak-Jaegermann,Geometry of families of random projections of symmetric convex bodies, Geometric and Functional Analysis11 (2001), 1282–1326.
V. D. Milman,Randomness and Pattern in Convex Geometric Analysis, Proceedings of ICM Berlin, Vol. 2, Documenta Mathematica, 1998, pp. 665–677.
V. D. Milman,Some applications of duality relations, inGeometric Aspects of Functional Analysis, (1989–90), Lecture Notes in Mathematics1469, Springer, Berlin, 1991, pp. 13–40.
V. D. Milman,A new proof of the theorem of A. Dvoretzky on sections of convex bodies, Functional Analysis and its Applications5 (1971), 28–37 (English translation).
V. D. Milman and G. Schechtmann,Asymptotic theory of finite-dimensional normed spaces, Lecture Notes in Mathematics1200, Springer-Verlag, Berlin, 1986.
V. D. Milman and G. Schechtman,Global versus local asymptotic theories of finite-dimensional normed spaces, Duke Mathematical Journal90 (1997), 73–93.
G. Pisier,Volumes of Convex Bodies and Banach Space Geometry, Cambridge University Press, 1989.
S. J. Szarek,The finite-dimensional basis problem with an appendix on nets of Grassman manifolds, Acta Mathematica151 (1983), 153–179.
S. J. Szarek,On the existence and uniqueness of complex structure and spaces with “few” operators, Transactions of the American Mathematical Society293 (1986), 339–353.
S. J. Szarek and N. Tomczak-Jaegermann,Saturating constructions for normed spaces, Geometric and Functional Analysis, to appear.
N. Tomczak-Jaegermann,Banach-Mazur Distances and Finite Dimensional Operator Ideals, Pitman Monographs, Longman, Harlow, 1989.
Author information
Authors and Affiliations
Corresponding author
Additional information
Research of this author was partially supported by KBN Grant no. 1 P03A 015 27.
This author holds the Canada Research Chair in Geometric Analysis.
Rights and permissions
About this article
Cite this article
Mankiewicz, P., Tomczak-Jaegermann, N. Low dimensional sections versus projections of convex bodies. Isr. J. Math. 153, 45–60 (2006). https://doi.org/10.1007/BF02771778
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02771778