Cylindrical Lévy Processes in the Lévy White Noise Approach

Lead Research Organisation: King's College London
Department Name: Mathematics

Abstract

This project is concerned with researching the properties of cylindrical Lévy processes in infinite dimensional spaces and developing techniques for analysing stochastic partial differential equations (SPDEs) where the driving noise is modelled using such processes. The content of the research will be novel mathematics in the area of probability. Applications of these techniques include the study of complex and/or noisy physical systems.

The particular research focus of this project is as follows: first, to determine the relationship between cylindrical Lévy processes and other forms of Lévy noises which are commonly in use in SPDEs, namely independently scattered random measures, Lévy sheets and Lévy-white-noise. Then, to analyse the 'jumps' of a cylindrical Lévy process, as the cylindrical process does not have jumps in the same sense as a classical stochastic process, and to investigate what consequences an understanding of these 'jumps', for example whether it is possible to derive a Lévy-Ito decomposition for the cylindrical process. Furthermore, to investigate which frameworks can be used to analyse the regularity of cylindrical Lévy processes, and in turn the regularity of solutions to SPDEs with a cylindrical Lévy process as the driving noise, and to develop a methodology for regularity analysis. Finally, further applications of the methods developed for the above questions in the study of cylindrical Lévy processes and SPDEs driven by such processes will be sought.

The approach that will be taken to answer these mathematical research questions and develop novel mathematical results will be to build upon the current theory of cylindrical Lévy processes and SPDEs utilising the methods of Probability Theory, Stochastic Analysis, Functional Analysis and Point-set Topology.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509498/1 01/10/2016 30/09/2021
1948378 Studentship EP/N509498/1 01/10/2017 31/12/2021 Matthew Griffiths
EP/R513064/1 01/10/2018 30/09/2023
1948378 Studentship EP/R513064/1 01/10/2017 31/12/2021 Matthew Griffiths
 
Description There are two common approaches for understanding Stochastic Partial Differential Equations (SPDEs), which may be described as a semi-group approach and a random field approach. The existing theory of cylindrical Levy processes is applicable to the semi-group approach. I have identified and characterised a sub-class of cylindrical Levy processes which are equivalent to a common model of Levy-type noise used in the random field approach, thus showing the cylindrical Levy process to be a good generalisation of common models of noise. Furthermore, I have developed a set of tools for measuring the spatial regularity of such noises.
Exploitation Route This research adds to the body of understanding of SPDEs, which have applications in Finance, Physics and Signal/ Image processing, among other fields.
Sectors Digital/Communication/Information Technologies (including Software),Financial Services, and Management Consultancy,Manufacturing, including Industrial Biotechology

URL https://arxiv.org/abs/1907.04193