A Hybrid Cosmological Hydrodynamic/N-body Code Based on the Weighted Essentially Non-Oscillatory Scheme

TL;DR

This paper introduces a new cosmological simulation code that combines high-order WENO schemes for hydrodynamics with a particle-mesh method for gravity, improving accuracy in modeling complex cosmic structures.

Contribution

The paper presents a novel hybrid code integrating WENO hydrodynamics with a particle-mesh gravity solver for enhanced cosmological simulations.

Findings

Successful simulation of intergalactic medium structures

Accurate modeling of Lyα forest in CDM scenario

Demonstrated stability and efficiency of the hybrid scheme

Abstract

We describe a newly developed cosmological hydrodynamics code based on the weighted essentially non-oscillatory (WENO) schemes for hyperbolic conservation laws. High order finite difference WENO schemes are designed for problems with piecewise smooth solutions containing discontinuities, and have been successful in applications for problems involving both shocks and complicated smooth solution structures. We couple hydrodynamics based on the WENO scheme with standard Poisson solver - particle-mesh (PM) algorithm for evolving the self-gravitating system. A third order total variation diminishing (TVD) Runge-Kutta scheme has been used for time-integration of the system. We brief the implementation of numerical technique. The cosmological applications in simulating intergalactic medium and Ly$\alpha$ forest in the CDM scenario are also presented.