I’m glad this kind of work is getting highlighted on HN, but this is an extremely misleading title, to the point of being outright false. As often happens, this appears to be due to PR titles being controlled by non-specialists, not the study authors.

While the work the authors do is important, in no sense does the tool they produced actually run a simulation.

A simulation implies a physical model and usually partial differential equations that are often solved on supercomputers, but here the neural network is rather interpolating some fixed simulation output in a purely data-driven way.

The simulations have not gotten faster due to neural networks, cosmologists have just gotten better at using them. Which is great!

Edit: see the sub-comment in the thread by crazygringo for the lead author’s take