About Ifan

Originally from Aberystwyth, I completed my BSc in Pure Mathematics at Swansea University, followed by an MRes in Stochastic Processes at the same department. During my MRes I worked with Dr Kristian Evans on pseudo-differential operators on the torus that extend to generators of Feller processes. After that, I completed an MSc at Warwick (MASDOC) taking modules from Analysis, Probability, Statistics and Numerical Analysis. For my MSc project I looked at a class of Markov processes on bounded domains generated by certain pseudodifferential operators.

I am in my final year of PhD under the supervision of Professor Vassili Kolokoltsov and Dr Larbi Alili, investigating generators of Feller processes on bounded domains. More specifically, I am looking at processes that live in a bounded domain, whose generator can be thought of as a generalization of certain fractional derivatives (Caputo and Riemann-Liouville derivatives). Using this probabilistic view point, one can look at certain equations involving these (generalised) fractional operators and thus obtain a probabilistic interpretation of the solution to such equations. I am also interesting in estimates for Green's functions of certain time-fractional evolution equations.

My mathematical interests lie mainly in Probability and Analysis.

Email: I.Johnston(at)warwick.ac.uk

Office: B0.24

Articles

• Greens function estimates for time fractional evolution equations (Joint with Vassili Kolokoltsov, Journal: Fractal and Fractional)
• Space-time coupled evolution equations and their stochastic solutions (Joint with Lorenzo Toniazzi & John Herman, submitted)
• Mixed linear fractional boundary value problems (Joint with Vassili Kolokoltsov, submitted)

Titles of talks given

• 'Fractional evoloution equations' - Speed talk at British Mathematical Colloquium, University of St Andrews, 11-14 June 2018.
• 'Fractional evolution equations and related two-sided estimates' - Postgraduate seminar, University of Warwick, 6 June 2018.
• 'Probabilistic methods in fractional calculus' - MASDOC Retreat, Peak District, 29 April - 2 May 2018.
• 'Two-sided estimates for the Greens function of fractional evolution equations' - Inequalities in PDEs/SPDEs, Bedlewo, Poland, 22-28 April 2018.
• 'Multidimensional fractional derivatives as generators of Feller processes on bounded domains', Bielefeld-Edinburgh-Swansea Stochastics Workshop, Bielefed, 26-28 March 2018
• 'Heat kernel estimates for fractional evolution equations' - International Conference on Stochastic Analysis and Applications, Bielefeld, 3-7 September 2018
• 'Heat kernel estimates for fractional evolution equations' - Probability and NonLocal PDE's, Swansea, 17-19 September 2018
• Fractional evolution equations and related estimates' - FCPNLO, Bilbao, September 26-28 2018

Other activities

2016-2018: Chairman of the MASDOC Student Staff Liason Committe.

2015-2018: PhD representative on the Welfare and Communications Committe (WCC) in the Statistics department.

2018: Organiser of Joint CDT Colloquium