English

Thin-thick approach to martingale representations on progressively enlarged filtrations

Probability 2024-06-21 v2

Abstract

We study the predictable representation property in the progressive enlargement F^\tau of a reference filtration F by a random time \tau. Our approach is based on the decomposition of any random time into two parts, one overlapping F-stopping times (thin part) and the other one that avoids F-stopping times (thick part). We assume that the F-thin part of \tau is nontrivial and prove a martingale representation theorem on F^\tau. We thus extend previous results dealing with F-avoiding random times. We collect some examples of application to the enlargement of the natural filtration of a L\'evy process.

Keywords

Cite

@article{arxiv.2406.08983,
  title  = {Thin-thick approach to martingale representations on progressively enlarged filtrations},
  author = {Antonella Calzolari and Barbara Torti},
  journal= {arXiv preprint arXiv:2406.08983},
  year   = {2024}
}
R2 v1 2026-06-28T17:04:21.457Z