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BOUNDS FOR EXPONENTIAL MOMENTS OF BESSEL PROCESSES

  • Makasu, Cloud (Departments of Mathematics and Applied Mathematics University of the Western Cape)
  • Received : 2018.10.12
  • Accepted : 2019.02.27
  • Published : 2019.09.30

Abstract

Let $0<{\alpha}<{\infty}$ be fixed, and let $X=(X_t)_{t{\geq}0}$ be a Bessel process with dimension $0<{\theta}{\leq}1$ starting at $x{\geq}0$. In this paper, it is proved that there are positive constants A and D depending only on ${\theta}$ and ${\alpha}$ such that $$E_x\({\exp}[{\alpha}\;\max_{0{\leq}t{\leq}{\tau}}\;X_t]\){\leq}AE_x\({\exp}[D_{\tau}]\)$$ for any stopping time ${\tau}$ of X. This inequality is also shown to be sharp.

Keywords

References

  1. D. L. Burkholder, Exit times of Brownian motion, harmonic majorization, and Hardy spaces, Advances in Math. 26 (1977), no. 2, 182-205. https://doi.org/10.1016/0001-8708(77)90029-9
  2. R. D. DeBlassie, Stopping times of Bessel processes, Ann. Probab. 15 (1987), no. 3, 1044-1051. https://projecteuclid.org/euclid.aop/1176992079 https://doi.org/10.1214/aop/1176992079
  3. L. E. Dubins, L. A. Shepp, and A. N. Shiryaev, Optimal stopping rules and maximal inequalities for Bessel processes, Theory Probab. Appl. 38 (1993), no. 2, 226-261; translated from Teor. Veroyatnost. i Primenen. 38 (1993), no. 2, 288-330. https://doi.org/10.1137/1138024
  4. S. E. Graversen and G. Peskir, Maximal inequalities for Bessel processes, J. Inequal. Appl. 2 (1998), no. 2, 99-119. https://doi.org/10.1155/S102558349800006X
  5. N. Ikeda and S. Watanabe, Stochastic Differential Equations and Diffusion Processes, North-Holland Mathematical Library, 24, North-Holland Publishing Co., Amsterdam, 1981.
  6. D. Lepingle, Une remarque sur les lois de certains temps d'atteinte, in Seminar on Probability, XV (Univ. Strasbourg, Strasbourg, 1979/1980) (French), 669-670, Lecture Notes in Math., 850, Springer, Berlin, 1981.
  7. D. Revuz and M. Yor, Continuous Martingales and Brownian Motion, Grundlehren der Mathematischen Wissenschaften, 293, Springer-Verlag, Berlin, 1991. https://doi.org/10.1007/978-3-662-21726-9
  8. W. A. Rosenkrantz and S. Sawyer, $L^p$ estimates for stopping times of Bessel processes, Z. Wahrsch. Verw. Gebiete 41 (1977), no. 2, 145-151. https://doi.org/10.1007/BF00538418
  9. A. Yasue, Bessel-like processes and SDE, J. Math. Kyoto Univ. 44 (2004), no. 4, 799-809. https://doi.org/10.1215/kjm/1250281699