Random walks and Lévy processes as rough paths

We consider random walks and Lévy processes in a homogeneous group G. For all p>0, we completely characterise (almost) all G-valued Lévy processes whose sample paths have finite p-variation, and give sufficient conditions under which a sequence of G-valued random walks converges in law to a L...

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Yazar: Chevyrev, I
Materyal Türü: Journal article
Baskı/Yayın Bilgisi: Springer Verlag 2017
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author Chevyrev, I
author_facet Chevyrev, I
author_sort Chevyrev, I
collection OXFORD
description We consider random walks and Lévy processes in a homogeneous group G. For all p>0, we completely characterise (almost) all G-valued Lévy processes whose sample paths have finite p-variation, and give sufficient conditions under which a sequence of G-valued random walks converges in law to a Lévy process in p-variation topology. In the case that G is the free nilpotent Lie group over Rd, so that processes of finite p-variation are identified with rough paths, we demonstrate applications of our results to weak convergence of stochastic flows and provide a Lévy–Khintchine formula for the characteristic function of the signature of a Lévy process. At the heart of our analysis is a criterion for tightness of p-variation for a collection of càdlàg strong Markov processes.
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spelling oxford-uuid:3eebfa48-d96e-428c-907b-b83c155351382022-03-26T14:28:40ZRandom walks and Lévy processes as rough pathsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3eebfa48-d96e-428c-907b-b83c15535138Symplectic Elements at OxfordSpringer Verlag2017Chevyrev, IWe consider random walks and Lévy processes in a homogeneous group G. For all p>0, we completely characterise (almost) all G-valued Lévy processes whose sample paths have finite p-variation, and give sufficient conditions under which a sequence of G-valued random walks converges in law to a Lévy process in p-variation topology. In the case that G is the free nilpotent Lie group over Rd, so that processes of finite p-variation are identified with rough paths, we demonstrate applications of our results to weak convergence of stochastic flows and provide a Lévy–Khintchine formula for the characteristic function of the signature of a Lévy process. At the heart of our analysis is a criterion for tightness of p-variation for a collection of càdlàg strong Markov processes.
spellingShingle Chevyrev, I
Random walks and Lévy processes as rough paths
title Random walks and Lévy processes as rough paths
title_full Random walks and Lévy processes as rough paths
title_fullStr Random walks and Lévy processes as rough paths
title_full_unstemmed Random walks and Lévy processes as rough paths
title_short Random walks and Lévy processes as rough paths
title_sort random walks and levy processes as rough paths
work_keys_str_mv AT chevyrevi randomwalksandlevyprocessesasroughpaths