Abstract: Current and next-generation large-scale structure surveys of the Universe are providing detailed measurements at extremely low levels of statistical uncertainty, accompanied by high resolution data. Commensurate numerical simulations that capture the extensive dynamic range of cosmological scales are required to provide accompanying theoretical predictions. Simulating baryonic effects on structure formation, in particular, is increasingly important to sufficiently model cosmological probes within the constricting precision demanded.
Historically, smoothed particle hydrodynamics (SPH) simulations have been a popular choice to resolve gas physics, owing to the numerical benefits of a Lagrangian particle-based methodology. We present a formulation of SPH (designated CRKSPH), that utilizes a first-order consistent reproducing kernel, a smoothing function that exactly interpolates linear fields with particle tracers. CRKSPH retains many benefits of traditional SPH methods (such as preserving Galilean invariance and manifest conservation of mass, momentum, and energy) while improving on many of the shortcomings, particularly the overly aggressive artificial viscosity and zeroth-order inaccuracy.