X: 03, 24-39, LNM 511 (1976)
JACOD, Jean;
MÉMIN, Jean
Un théorème de représentation des martingales pour les ensembles régénératifs (
Martingale theory,
Markov processes,
Stochastic calculus)
The natural filtration of a regenerative set $M$ is that of the corresponding ``age process''. There is a natural optional random measure $\mu$ carried by the right endppoints of intervals contiguous to $M$, each endpoint carrying a mass equal to the length of its interval. Let $\nu$ be the previsible compensator of $\mu$. It is shown that, if $M$ has an empty interior the martingale measure $\mu-\nu$ has the previsible representation property in the natural filtration
Comment: Martingales in the filtration of a random set (not necessarily regenerative) have been studied by Azéma in
1932. In the case of the set of zeros of Brownian motion, the martingale considered here is the second ``Azéma's martingale'' (not the well known one which has the chaotic representation property)
Keywords: Regenerative sets,
Renewal theory,
Stochastic integrals,
Previsible representationNature: Original
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