This website is something of a relic of my former life as an observational cosmologist, where I worked at the Astrophysics Group at University College London in the UK, as well as the Jet Propulsion Laboratory, California Institute of Technology, and the Institute d'Astrophysique de Paris. I am now a Senior Data Scientist at Fidelity International in the City of London, where I am working on techniques that apply insights from behavioural science to help us make better decisions.

My academic research focused primarily on methods for the analysis of astrophysical data. I was particularly interested in reliable inference about weak gravitational lensing from large imaging survey experiments such as the Dark Energy Survey, WFIRST, or Euclid. This meant that I used to think about pixels, images, and noisy data, a lot.
  • An ADS list of my accepted publications in peer-reviewed journals can be found here and a selection of free preprints can be found on arXiv here
  • A more recent, post-cosmology project in a whole new field was some work with my friend Joseph Sherwood at Imperial on improving experimental techniques for assessing the efficacy of glaucoma drug treatments
  • My Linkedin employment profile and history can be found at https://uk.linkedin.com/in/barnabyrowe
  • My Google Scholar profile page, and Google's estimate of my (very) slowly increasing h-index, can be found here

Past projects


With Rachel Mandelbaum I was Co-PI of the GREAT3 Challenge project (the third GRavitational lEnsing Accuracy Testing Challenge). For information about the Challenge, please see the GREAT3 Challenge web page.


The GREAT3 Challenge data will be built using code from an open-source software project called GalSim: the modular galaxy image simulation toolkit. This is an ambitious attempt to provide the community with a free, well-vetted toolkit for simulating realistic galaxy images based on physical models of telescope optics, the atmosphere, and using real galaxy images from the Hubble Space Telescope. Along with close collaborators like Rachel, and Mike Jarvis (UPenn), GalSim is blessed by a wonderful team of GalSim developers.

The Dark Energy Survey

At University College London I was part of the Capitalizing on Gravitational Shear (COGS)project (PI: Sarah Bridle), and together with Sarah Bridle, Joe Zuntz, Lisa Voigt, Michael Hirsch & Tomasz Kacprzak we worked towards the accurate measurement of cosmological lensing information in the Dark Energy Survey (DES). This huge telescope project is designed to probe the origin of the accelerating universe and help uncover the nature of dark energy by measuring the 14-billion-year history of cosmic expansion with high precision.


A big part of the work for DES is the open-source im3shape galaxy shape estimation software, described here. This is a maximum-likelihood galaxy shape inference tool, designed from the outset to be as modular and easily extensible as possible. The project is led by Joe Zuntz, and so far results are extremely encouraging in terms of both robustness and overall bias.

Image sampling in the focal plane of a Dark Energy space mission: IMCOM

In a very enjoyable project funded by the NASA WFIRST mission, I worked on the implementation of an image combination algorithm devised by Christopher Hirata (who would probably not thank me for posting this link) which we called IMCOM. The paper is available here.

The IMCOM algorithm allows for careful treatment of aliasing in undersampled imaging data, and can be used to test the feasibility of multi-exposure observing strategies for space-based survey missions. Recently, we also used IMCOM to explore focal plane undersampling for an optical space mission such as Euclid (see here) and will soon be publishing some laboratory detector analysis work for WFIRST that makes heavy use of IMCOM.

The IMCOM software is now freely available, and can be downloaded using the link below.


A modern analysis of the current largest area of deep, optical, Canada-France-Hawaii Telescope data using gravitational lensing. A forerunner of DES, the CFHTLenS project has constructed the largest map of dark matter yet made, and placed new constraints on the validity of Einstein's General Relativity on cosmological scales.

Public software

Some of the freely-available software I have been involved with helping build in support of the projects described above: