quantizer: a new collisionless N-body code optimized for small-scale devices.

We present quantizer , a new collisionless N -body code tailored for cosmological and galaxy-scale simulations. The code uses the particle-mesh method, combined with a novel adaptive mesh refinement (AMR) technique. The design of the AMR method of quantizer maximizes the efficient use of refinement zones by combining a cell-by-cell scheme with parallelization-friendly regular patches. We test the code using three astrophysical systems: a binary system of two particles without AMR to test orbital accuracy; an isolated elliptical galaxy modelled as a Plummer sphere; and a merger of two disc galaxies. Comparisons are made with the well-known particle-mesh AMR code ramses , and with our own direct particle-particle solver. The results show that the accuracy of quantizer is equal to or better than ramses , and the runtime is approximately 2.5 to 10 times faster than that code, depending on the problem. [ABSTRACT FROM AUTHOR]