Bernoulli

• Bernoulli
• Volume 23, Number 1 (2017), 503-521.

Viscosity characterization of the explosion time distribution for diffusions

Yinghui Wang

Abstract

We show that the tail distribution $U$ of the explosion time for a multidimensional diffusion (and more generally, a suitable function $\mathscr{U}$ of the Feynman–Kac type involving the explosion time) is a viscosity solution of an associated parabolic partial differential equation (PDE), provided that the dispersion and drift coefficients of the diffusion are continuous. This generalizes a result of Karatzas and Ruf [Probab. Theory Related Fields (2015) To appear], who characterize $U$ as a classical solution of a Cauchy problem for the PDE in the one-dimensional case, under the stronger condition of local Hölder continuity on the coefficients. We also extend their result to $\mathscr{U}$ in the one-dimensional case by establishing the joint continuity of $\mathscr{U}$. Furthermore, we show that $\mathscr{U}$ is dominated by any nonnegative classical supersolution of this Cauchy problem. Finally, we consider another notion of weak solvability, that of the distributional (sub/super)solution, and show that $\mathscr{U}$ is no greater than any nonnegative distributional supersolution of the relevant PDE.

Article information

Source
Bernoulli, Volume 23, Number 1 (2017), 503-521.

Dates
Revised: July 2015
First available in Project Euclid: 27 September 2016

https://projecteuclid.org/euclid.bj/1475001363

Digital Object Identifier
doi:10.3150/15-BEJ752

Mathematical Reviews number (MathSciNet)
MR3556781

Zentralblatt MATH identifier
1361.60069

Citation

Wang, Yinghui. Viscosity characterization of the explosion time distribution for diffusions. Bernoulli 23 (2017), no. 1, 503--521. doi:10.3150/15-BEJ752. https://projecteuclid.org/euclid.bj/1475001363

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