It all started back at the Universtity of Glasgow...
BSc Hons. 1st Class, Physics and Astronomy, University of Glasgow 1989
PhD Wave Propagation in Equal Mass Plasmas, University of Glasgow 1992
I worked in solar physics, developing large scale structure models of the solar corona, among other things to do with the Sun.
Back in Scotland, I took some brief time away from academia and dipped my toes in the world of professional software development (very early days of C++!).
Back in Glasgow, I ran various IT systems in the astronomy group for a few years, as well as supporting departmental IT.
The to the grid! The projects to support computing for the Large Hadron Collider at CERN were starting and I joined GridPP to work as their Data Management coordinator, as well as later taking over the running of the ScotGrid Distributed Tier-2 (with sites in Glasgow, Edinburgh and Durham).
Later I travelled to be based at CERN and help the ATLAS experiment with their first data taking runs.
Developing my expertise in data management, I joined the CERN EP-ADP group to help design the next version of Rucio, which has become the de-facto standard tool for large scale scientific data management (so we must have done a good job!).
After that, I returned to work for Glasgow, now taking senior roles in ATLAS software development, including Core Software Coordinator and overall Software Coordinator.
At this time the HEP Software Foundation was gathering momentum - I rejoined CERN, now to work in the Software for Experiments group, supporting the HSF, as well as leading development of software for the high-luminosity upgrade and beyond, in the AIDAinnova and the CERN EP R&D projects.
Currently my development efforts are focusing using Julia as a future language for high-energy physics.
This a non-exhaustive selection of highlight invited talks which I have given:
Julia in HEP, Computing and High Energy Physics 2024 (Krakow), October 2024
HEP Software Status and Future, invited talk at the International Committee for Future Accelerators Seminar 2023, November 2023, Hamburg
The interface to computing - HSF perspective, Einstein Telescope Computing and Data Requirements Workshop, October 2023, Geneva
Computing in Physics, invited talk at the German Helmholtz Association meeting, September 2023, Karlsruhe
Software and Computing R&D, 30th International Symposium on Lepton Photon Interactions at High Energies, January 2022
Software R&D an International Perspective, invited talk at the UK PPTAP Computing & Software Roadmap Workshop, July 2021
As an ATLAS author I have more papers than you can shake a stick at... My current authorship listing is on INSPIRE.
Some highlight recent papers, in which I played a major role, are:
Polyglot Jet Finding, EPJ Web of Conferences (CHEP 20233), 10.1051/epjconf/202429505017, 2024
Potential of the Julia Programming Language for High Energy Physics Computing, Computing and Software for Big Science, 10.1007/s41781-023-00104-x, 2023
A Roadmap for HEP Software and Computing R&D for the 2020s, editor. Computing and Software for Big Science, 10.1007/s41781-018-0018-8, 2019
Here is my publication list from earlier in my career, when I worked in plasma physics and solar physics:
K Petrovay, J C Brown, L Van Driel-Gesztelyi, L Fletcher, M Marik, and G A Stewart. Asymmeteric flux loops in active regions, ii. Solar Physics, 127:51-64, 1990.
G A Stewart and E W Laing. Wave propagation in equal mass plasmas. Journal of Plasma Physics, 47:295-319, 1992.
G A Stewart. Nonlinear electrostatic waves in equal mass plasmas. Journal of Plasma Physics, 52:521-536, 1993.
S Bravo and G A Stewart. Evolution of polar coronal holes and sunspots during cycles 21 and 22. Solar Physics, 154:377-384, 1994.
S Bravo and G A Stewart. The inclination of the heliomagnetic equator and the presence of an inclined relic field in the sun. Astrophysical Journal, 446:431-434, 1995.
G A Stewart and S Bravo. Solar flare activity and the large scale structure of the coronal neutral line. Solar Physics, 160:331-341, 1995.
N Ya Kotsarenko and G A Stewart. On the cutoff frequency of fast electromagnetic waves in a highly magnetised plasma. Physica Scripta, 55:88-89, 1995.
S Bravo and G A Stewart. Latitudinal variation of the helospheric magnetic field during the solar minimum. Geophysical Research Letters, 23:3271-3274, 1996.
N Ya Kotsarenko, G A Stewart, and V Vysloukh. Nonlinear low frequency electromagnetic waves in a relativistic electron-positron plasma. Astrophysics and Space Science, 243:427-437, 1996.
G A Stewart and S Bravo. Latitudinal solar wind velocity variations from polar coronal holes: A self-consistent mhd model. Journal of Geophysical Research, 102:11263-11272, 1997.
S Bravo and G A Stewart. The correlation between sunspot and coronal hole cycles and a forecast of the maximum of sunspot cycle 23. Solar Physics, 173:193-198, 1997.
S Bravo and G A Stewart. Fast and slow wind from solar coronal holes. Astrophysical Journal, 489:992-999, 1997.
S Bravo, G A Stewart, and X Blanco-Cano. The varying multipolar structure of the sun's magnetic field and the evolution of the solar magnetosphere through the solar cycle. Solar Physics, 179:223-235, 1998.
N Ya Kotsarenko, S Koshevaya, G A Stewart, and D Maravilla. Electrostatic spatially limited solitons in a magnetised dusty plasma. Planetary and Space Science, 46:429-433, 1998.
N Ya Kotsarenko, G A Stewart, J J S Mondragon, S Koshevaya, A N Kotsarenko, and P A Marquez. Nonlinear electromagnetic waves in a multicomponent plasma. Physica Scripta, 59:302-307, 1999.
S Bravo, E Aguilar, X Blanco-Cano, and G A Stewart. Coronal magnetic structures associated with interplanetary clouds. Solar Physics, 188:163-168, 1999.