Hostname: page-component-8448b6f56d-mp689 Total loading time: 0 Render date: 2024-04-19T23:20:31.497Z Has data issue: false hasContentIssue false

REMARKS ON MAXIMAL OPERATORS OVER ARBITRARY SETS OF DIRECTIONS

Published online by Cambridge University Press:  01 November 1999

NETS HAWK KATZ
Affiliation:
Department of Mathematics, Edinburgh University, James Clerk Maxwell Building, The King's Buildings, Mayfield Road, Edinburgh EH9 3JZ
Get access

Abstract

Throughout this paper, we shall let Σ be a subset of [0, 1] having cardinality N. We shall consider Σ to be a set of slopes, and for any s∈Σ, we shall let es be the unit vector of slope s in ℝ2. Then, following [7], we define the maximal operator on ℝ2 associated with the set Σ by

formula here

The history of the bounds obtained on [Mfr ]0Σ is quite curious. The earliest study of related operators was carried out by Cordoba [2]. He obtained a bound of C√(1+logN) on the L2 operator norm of the Kakeya maximal operator over rectangles of length 1 and eccentricity N. This operator is analogous to [Mfr ]0Σ with

formula here

However, for arbitrary sets Σ, the best known result seems to be C(1+logN). This follows from Lemma 5.1 in [1], but a point of view which produces a proof appears already in [8]. However, in this paper, we prove the following.

Type
NOTES AND PAPERS
Copyright
© The London Mathematical Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)