Simulating the Universe Using Modern C++
Presentation Slides, PDFs, Source Code and other presenter materials are available at:https://github.com/CppCon/CppCon2014
What is the link between C++11/14, parallelism and the open question of the origin of the accelerated expansion of the Universe ? Answer: numerical cosmology and all the techniques to make the best out of supercomputers to shed a new light on unsolved problem in physics. In this talk, I will present the numerical lessons coming from the Full Universe Run, a numerical experiment realized in 2012 on the entire Curie thin-nodes Supercomputer to simulate the evolution of cosmological structures during the last 13.7 billion years. I will focus on how this experiment has changed our view on software design in astrophysics and how we started to implement new approaches using C++11, template metaprogramming, constant expressions and std::thread in order to maximize both genericity and performance. I will also discuss optimization issues related to data locality, cache efficiency and spatial trees which are extensively used in our domain. I will also try to give some inputs on the cultural challenges raised by the introduction of C++11/14 in our domain. This talk will be concluded by thoughts on the needs of computational physicists and how C++17 may help us to solve some of the open problems we are currently facing.
Vincent Reverdy is a Ph.D. student in numerical cosmology at the Observatory of Paris. He studies the propagation of light according to general relativity in order to probe the unexplained accelerated expansion of the Universe. In this context, he is using supercomputing facilities on a daily basis and he develops scientific codes for these facilities, mainly in C++.
He is working now on approaches based on template metaprogramming to make the best out of supercomputers and to facilitate the implementation of non-standard cosmological models. Since the Bristol committee meeting, he also follows and contributes to the online discussions on the evolution of C++.
Videos Filmed & Edited by Bash Films: http://www.BashFilms.com