\ John Wormell, Sydney Mathematics & Statistics

John Wormell

The student atop a (very minor) Alp Postgraduate student in the School of Mathematics and Statistics at the University of Sydney.

Postal address: John Wormell
School of Mathematics and Statistics F07
University of Sydney NSW 2006
Office: Room 489 Carslaw Building
Email: J.Wormell@maths.usyd.edu.au

Research Interests

Working under Prof Georg Gottwald on chaotic dynamical systems, mostly using one-dimensional systems as a model. Mostly, I am developing spectral methods for transfer operators of one-dimensional systems, enabling fast and highly accurate estimation of statistical properties.


Wormell, J.P. Spectral Galerkin methods for transfer operators in uniformly expanding dynamics (2017). Preprint

Gottwald G.A., Wormell, J.P. and Wouters, J., On spurious detection of linear response and misuse of the fluctuation-dissipation theorem in finite time series Physica D 331 (2016) 89-101. Preprint, DOI

Computer packages

Poltergeist.jl: Julia package for adaptive calculation of statistical properties of 1D maps via spectral methods.


Spectral methods for intermittent maps using Abel functions. Poster at Foundations of Computational Mathematics conference (2017).

Fast approximation techniques for intermittent maps. Poster at Advances in Ergodic Theory, Hyperbolic Dynamics and Statistical Laws (2017). Prize for best poster.

Approximating 1D chaotic dynamics in a Fourier basis. Poster at Mixing Flows and Averaging Methods workshop, ESI Vienna (2016). Link

The mathematics of biological pattern formation, or How the Leopard Got Its Spots. Talk for Sydney University Mathematics Society (2016). Abstract

Minding your p's and q's: adventures in statistical inference. Talk for Sydney University Mathematics Society (2014). Abstract