On expected signatures and signature cumulants in semimartingale models

Fuente: arXiv
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Auteurs principaux: Friz, Peter K., Hager, Paul P., Tapia, Nikolas
Format: Preprint
Publié: 2024
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author Friz, Peter K.
Hager, Paul P.
Tapia, Nikolas
author_facet Friz, Peter K.
Hager, Paul P.
Tapia, Nikolas
contents The concept of signatures and expected signatures is vital in data science, especially for sequential data analysis. The signature transform, a Cartan type development, translates paths into high-dimensional feature vectors, capturing their intrinsic characteristics. Under natural conditions, the expectation of the signature determines the law of the signature, providing a statistical summary of the data distribution. This property facilitates robust modeling and inference in machine learning and stochastic processes. Building on previous work by the present authors [Unified signature cumulants and generalized Magnus expansions, FoM Sigma '22] we here revisit the actual computation of expected signatures, in a general semimartingale setting. Several new formulae are given. A log-transform of (expected) signatures leads to log-signatures (signature cumulants), offering a significant reduction in complexity.
format Preprint
id arxiv_https___arxiv_org_abs_2408_05085
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle On expected signatures and signature cumulants in semimartingale models
Friz, Peter K.
Hager, Paul P.
Tapia, Nikolas
Machine Learning
Probability
60L10, 60L90, 60E10, 60G44, 60G48, 60G51, 60J76
The concept of signatures and expected signatures is vital in data science, especially for sequential data analysis. The signature transform, a Cartan type development, translates paths into high-dimensional feature vectors, capturing their intrinsic characteristics. Under natural conditions, the expectation of the signature determines the law of the signature, providing a statistical summary of the data distribution. This property facilitates robust modeling and inference in machine learning and stochastic processes. Building on previous work by the present authors [Unified signature cumulants and generalized Magnus expansions, FoM Sigma '22] we here revisit the actual computation of expected signatures, in a general semimartingale setting. Several new formulae are given. A log-transform of (expected) signatures leads to log-signatures (signature cumulants), offering a significant reduction in complexity.
title On expected signatures and signature cumulants in semimartingale models
topic Machine Learning
Probability
60L10, 60L90, 60E10, 60G44, 60G48, 60G51, 60J76
url https://arxiv.org/abs/2408.05085