Home | Contents | Submissions, editors, etc. | Login | Search | EJP
 Electronic Communications in Probability > Vol. 14 (2009) > Paper 2 open journal systems 


Sharp maximal inequality for martingales and stochastic integrals

Adam Osekowski, University of Warsaw


Abstract
Let $X=(X_t)_{tgeq 0}$ be a martingale and $H=(H_t)_{tgeq 0}$ be a predictable process taking values in $[-1,1]$. Let $Y$ denote the stochastic integral of $H$ with respect to $X$. We show that $$ ||sup_{tgeq 0}Y_t||_1 leq beta_0 ||sup_{tgeq 0}|X_t|||_1,$$ where $beta_0=2,0856ldots$ is the best possible. Furthermore, if, in addition, $X$ is nonnegative, then $$ ||sup_{tgeq 0}Y_t||_1 leq beta_0^+ ||sup_{tgeq 0}X_t||_1,$$ where $beta_0^+=frac{14}{9}$ is the best possible.


Full text: PDF

Pages: 17-30

Published on: January 23, 2009


Bibliography
  1. K. Bichteler. Stochastic integration and $L^p$-theory of semimartingales . Ann. Probab. 9 (1981), 49-89. Math. Review 82g:60071
  2. D. L. Burkholder. Boundary value problems and sharp inequalities for martingale transforms. Ann. Probab. 12 (1984), 647-702. Math. Review 86b:60080
  3. D. L. Burkholder. Explorations in martingale theory and its applications. Ecole d'Ete de Probabilités de Saint-Flour XIX---1989, 1--66, Lecture Notes in Math., 1464, Springer, Berlin, 1991. Math. Review 92m:60037
  4. D. L. Burkholder. Sharp norm comparison of martingale maximal functions and stochastic integrals. Proceedings of the Norbert Wiener Centenary Congress, 1994 (East Lansing, MI, 1994), 343-358, Proc. Sympos. Appl. Math., 52, Amer. Math. Soc., Providence RI, 1997 Math. Review 98f:60103
  5. A. Osekowski. Sharp maximal inequality for stochastic integrals. Proc. Amer. Math. Soc. 136 (2008), 2951-2958. Math. Review number not available
















Research
Support Tool
Capture Cite
View Metadata
Printer Friendly
Context
Author Address
Action
Email Author
Email Others


Home | Contents | Submissions, editors, etc. | Login | Search | EJP

Electronic Communications in Probability. ISSN: 1083-589X