2020/09/14 by G. Aguilar-Argüello, Aguilar-Argüello, G., O. Valenzuela +7
Engineering · Mathematics · Physics and Astronomy · #Computational Physics (physics.comp-ph) #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Frequency Control in Power Systems #Magnetic confinement fusion research #Numerical methods for differential equations
paper · pdf · doi:10.48550/arxiv.2009.06133
openalex publication_date 2020/09/14 · openalex created_date 2023/02/11 · openalex updated_date 2026/07/28
The large dynamic range in some astrophysical N-body problems led to the use of adaptive multi-time-steps; however, the search for optimal strategies is still challenging. We numerically quantify the performance of the hierarchical Hamiltonian Splitting (HHS) integrator for collisionless simulations using a direct summation code. We compare HHS with the constant global time-step leapfrog integrator, and with the adaptive one (AKDK). We find that HHS is approximately reversible, whereas AKDK not. Therefore, it is possible to find a combination of parameters where the energy drift is considerably milder for HHS, resulting in a better performance. We conclude that HHS is an attractive alternative to AKDK, and it is certainly advantageous for direct summation and P3M codes. Also, we find advantages with GADGET4 (Tree/FMM) HHS implementation that are worth exploring further.