Astrophysical and cosmological simulations are often insightful. They're also very cross-disciplinary; besides the obvious astrophysics, there's networking and sysadmin, parallel computing and algorithm theory (so that the simulation programs are actually fast but still accurate), systems design, and even a bit of graphic design for the visualisations.

Some of my favourite simulation projects:

- IllustrisTNG: https://www.tng-project.org/

- SWIFT: https://swift.dur.ac.uk/

- CO5BOLD: https://www.astro.uu.se/~bf/co5bold_main.html (which produced these animations of a red-giant star: https://www.astro.uu.se/~bf/movie/AGBmovie.html)

- AbacusSummit: https://abacussummit.readthedocs.io/en/latest/

And I can add the simulations in the article, too.

Supernova simulations are especially interesting too. I have heard them described as the only time in physics when all 4 of the fundamental forces are important. The explosion can be quite finicky too. If I remember right, you can't get supernova to explode properly in 1D simulations, only in higher dimensions. This was a mystery until the realization that turbulence is necessary for supernova to trigger--there is no turbulent flow in 1D.

Whoa. I didn't know the accretion theory of Ia supernovae was dead, much less that it had been since 2011.

This seems to be the paper https://academic.oup.com/mnras/article/517/4/5260/6779709

Wouldn't double detonation show up as variance in the brightness?

Or widening of the peak. If one type Ia supernova goes 1,2,3,2,1, the sum of two could go

    1+0=1
    2+1=3
    3+2=5
    2+3=5
    1+2=3
    0+1=1