We work among extraordinary people doing extraordinary things; get to know some of them by reading these quick-fire interviews.
Name: Deaglan Bartlett
Job title: Eric and Wendy Schmidt AI in Science Postdoctoral Fellow
What are you currently working on?
I am an Eric and Wendy Schmidt AI in Science Postdoctoral Fellow within Astrophysics, where I work on projects at the border of artificial intelligence and Bayesian inference problems, within the framework of applications to cosmology. I also hold the International Astronomical Union (IAU) The Gruber Foundation (TGF) Fellowship in Astrophysics for 2025/26, and will join Brasenose College with a Nicholas Kurti Junior Research Fellowship in October for 2025-2028.
I am interested in statistical and machine learning methodology in astrophysics and cosmology, Bayesian large-scale structure inference, field-level inference, and probing dark energy and constraining dark matter with astronomical surveys. I also work on accelerating cosmological simulations using machine learning methods and methodological improvements and applications of symbolic regression, a machine-learning technique which directly learns analytic laws from data.
I was previously a postdoctoral fellow at the Institut d’Astrophysique de Paris, where I was supported by the Simons Foundation on Learning the Universe. I continue to work within this collaboration, and co-lead the Accelerated Forward Modelling working group. I obtained my DPhil in Astrophysics at Oriel College, Oxford under the supervision of Professor Pedro Ferreira and Dr Harry Desmond. I was also the Graduate Teaching and Research Scholar at Oriel College from 2020 to 2022. My DPhil research focused on using the morphology and kinematics of galaxies to learn about galaxy formation and to constrain new physics (theories beyond the standard models of cosmology (ΛCDM) and particle physics (SM)).
Describe a typical day
A typical day starts early – I like to be at my desk before 9am to get a head start on work before meetings begin. I usually begin by scanning the latest arXiv papers and responding to emails that came in overnight. Much of my research revolves around Python programming, whether it’s using symbolic regression to develop new approximations for physical processes, building pipelines for simulation-based inference in large-scale structure studies, or managing issues on GitHub. Writing papers and internal notes via Overleaf is also a regular part of the workflow. Afternoons are often filled with meetings, usually with collaborators and students based in the UK, US, and across Europe. I typically round off the day by catching up on Slack messages before heading home to Reading, where I live with my partner.
If you had an entire day at your disposal (not at work), what would be your ideal way to spend it?
I am a massive cricket fan, so it would be hard to beat a sunny day at Lord’s watching a test match (and no – five days is not too long for a match!). That said, I wouldn’t say no to a similarly sunny day at the beach. I would want to spend the evening relaxing with friends and family – perhaps having a barbecue and soaking up the late summer sun. Really, just a perfect English summer’s day.
What is your favourite place in Oxford?
I have only recently returned to Oxford, but looking back at photos from my time as a DPhil student, it’s clear I had a real fondness for formals so I would have to say my favourite place is a college hall. I also used to live next door to The Bear pub, which made for plenty of fun evenings and good memories there too.
Plan B: what would you be if you weren’t doing the job you are currently doing?
I always joke that, given my love of pastries, I should open a patisserie or café. Living in Paris for nearly three years only reinforced that dream (although I’m under no illusion about how much hard work it would be!). Before I got hooked on physics as a teenager, I probably would have said a medical doctor. With my brother in the police and my sister a children’s nurse, it’s easy to see why a role focused on public service would have appealed to me.
What discovery would you like to see in your lifetime?
I would love to witness a major breakthrough in our understanding of dark matter or dark energy – discoveries that would fundamentally reshape our view of the Universe and resolve questions that have puzzled cosmologists for decades. At the same time, I hope to see advances in science and technology that help address pressing global challenges like climate change. Whether through new clean energy solutions or innovations inspired by fundamental research, it would be deeply rewarding to see discoveries that lead to meaningful, lasting impact on our planet.