Causal functional calculus

We construct a new topology on the space of stopped paths and introduce a calculus for causal functionals on generic domains of this space. We propose a generic approach to pathwise integration without any assumption on the variation index of a path and obtain functional change of variable formulae...

Full description

Bibliographic Details
Main Authors: Henry Chiu, Rama Cont
Format: Journal article
Language:English
Published: London Mathematical Society 2022
_version_ 1797112556760858624
author Henry Chiu
Rama Cont
author_facet Henry Chiu
Rama Cont
author_sort Henry Chiu
collection OXFORD
description We construct a new topology on the space of stopped paths and introduce a calculus for causal functionals on generic domains of this space. We propose a generic approach to pathwise integration without any assumption on the variation index of a path and obtain functional change of variable formulae which extend the results of Föllmer [Séminaire de probabilités 15 (1981), 143–150] and Cont and Fournié [J. Funct. Anal. 259 (2010), no. 4, 1043–1072] to a larger class of functionals, including Föllmer's pathwise integrals. We show that a class of smooth functionals possess a pathwise analogue of the martingale property. For paths that possess finite quadratic variation, our approach extends the Föllmer–Ito calculus and removes previous restriction on the time partition sequence. We introduce a foliation structure on this path space and show that harmonic functionals may be represented as pathwise integrals of closed 1-forms.
first_indexed 2024-03-07T08:27:17Z
format Journal article
id oxford-uuid:2d62854e-2cdc-4bf4-b823-9997436cfe45
institution University of Oxford
language English
last_indexed 2024-03-07T08:27:17Z
publishDate 2022
publisher London Mathematical Society
record_format dspace
spelling oxford-uuid:2d62854e-2cdc-4bf4-b823-9997436cfe452024-02-22T14:53:20ZCausal functional calculusJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2d62854e-2cdc-4bf4-b823-9997436cfe45EnglishSymplectic ElementsLondon Mathematical Society2022Henry ChiuRama ContWe construct a new topology on the space of stopped paths and introduce a calculus for causal functionals on generic domains of this space. We propose a generic approach to pathwise integration without any assumption on the variation index of a path and obtain functional change of variable formulae which extend the results of Föllmer [Séminaire de probabilités 15 (1981), 143–150] and Cont and Fournié [J. Funct. Anal. 259 (2010), no. 4, 1043–1072] to a larger class of functionals, including Föllmer's pathwise integrals. We show that a class of smooth functionals possess a pathwise analogue of the martingale property. For paths that possess finite quadratic variation, our approach extends the Föllmer–Ito calculus and removes previous restriction on the time partition sequence. We introduce a foliation structure on this path space and show that harmonic functionals may be represented as pathwise integrals of closed 1-forms.
spellingShingle Henry Chiu
Rama Cont
Causal functional calculus
title Causal functional calculus
title_full Causal functional calculus
title_fullStr Causal functional calculus
title_full_unstemmed Causal functional calculus
title_short Causal functional calculus
title_sort causal functional calculus
work_keys_str_mv AT henrychiu causalfunctionalcalculus
AT ramacont causalfunctionalcalculus