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Main Authors: Arharas, Ihsan, Bouhadou, Siham, Hilbert, Astrid, Ouknine, Youssef
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2303.16847
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author Arharas, Ihsan
Bouhadou, Siham
Hilbert, Astrid
Ouknine, Youssef
author_facet Arharas, Ihsan
Bouhadou, Siham
Hilbert, Astrid
Ouknine, Youssef
contents We consider the optimal stopping time problem under model uncertainty $R(v)= {\text{ess}\sup\limits}_{ \mathbb{P} \in \mathcal{P}} {\text{ess}\sup\limits}_{τ\in \mathcal{S}_v} E^\mathbb{P}[Y(τ) \vert \mathcal{F}_v]$, for every stopping time $v$, set in the framework of families of random variables indexed by stopping times. This setting is more general than the classical setup of stochastic processes, and particularly allows for general payoff processes that are not necessarily right-continuous. Under weaker integrability, and regularity assumptions on the reward family $Y=(Y(v), v\in \mathcal{S})$, we show the existence of an optimal stopping time. We then proceed to find sufficient conditions for the existence of an optimal model. For this purpose, we present a universal Doob-Meyer-Mertens's decomposition for the Snell envelope family associated with $Y$ in the sense that it holds simultaneously for all $\mathbb{P} \in \mathcal{P}$. This decomposition is then employed to prove the existence of an optimal probability model and study its properties.
format Preprint
id arxiv_https___arxiv_org_abs_2303_16847
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Optimal Stopping Under Model Uncertainty in a General Setting
Arharas, Ihsan
Bouhadou, Siham
Hilbert, Astrid
Ouknine, Youssef
Probability
60G40, 60H30, 60G07
We consider the optimal stopping time problem under model uncertainty $R(v)= {\text{ess}\sup\limits}_{ \mathbb{P} \in \mathcal{P}} {\text{ess}\sup\limits}_{τ\in \mathcal{S}_v} E^\mathbb{P}[Y(τ) \vert \mathcal{F}_v]$, for every stopping time $v$, set in the framework of families of random variables indexed by stopping times. This setting is more general than the classical setup of stochastic processes, and particularly allows for general payoff processes that are not necessarily right-continuous. Under weaker integrability, and regularity assumptions on the reward family $Y=(Y(v), v\in \mathcal{S})$, we show the existence of an optimal stopping time. We then proceed to find sufficient conditions for the existence of an optimal model. For this purpose, we present a universal Doob-Meyer-Mertens's decomposition for the Snell envelope family associated with $Y$ in the sense that it holds simultaneously for all $\mathbb{P} \in \mathcal{P}$. This decomposition is then employed to prove the existence of an optimal probability model and study its properties.
title Optimal Stopping Under Model Uncertainty in a General Setting
topic Probability
60G40, 60H30, 60G07
url https://arxiv.org/abs/2303.16847