Abstract
We study the following problem concerning stopped N-dimensional Brownian motion: Compute the maximal function of the process, ignoring those times when it is in some fixed region R. Suppose this modified maximal function belongs to LqFor what regions R can we conclude that the unrestricted maximal function belongs to Lqc! A sufficient condition on R is that there exist p > q and a function w, harmonic in /?, such that \x\p^ u(x) < C\x\p+ C, x Çz R, for some constant C. We give applications to analytic and harmonic functions, and to weak inequalities for exit times.
Original language | English (US) |
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Pages (from-to) | 719-731 |
Number of pages | 13 |
Journal | Transactions of the American Mathematical Society |
Volume | 271 |
Issue number | 2 |
DOIs | |
State | Published - Jun 1982 |
Externally published | Yes |
Keywords
- Brownian motion
- Exit time
- Hardy space
- Harmonic majorization
- Maximal function
ASJC Scopus subject areas
- General Mathematics
- Applied Mathematics