GPU-Accelerated Particle-Mesh Cosmological Simulations with NVIDIA Warp: Performance and Accuracy Validation

Abstract: Modern cosmological analyses increasingly rely on large ensembles of N-body simulations, but their computational cost on traditional CPU architectures presents a significant bottleneck. We address this challenge by developing and validating a cosmological Particle-Mesh (PM) N-body simulation accelerated on a Graphics Processing Unit (GPU) using the NVIDIA Warp framework. Our method evolves particles in a volume from initial conditions at generated with second-order Lagrangian Perturbation Theory (2LPT) (2LPT). To rigorously assess physical accuracy and quantify statistical variance, we execute an ensemble of ten independent realizations and compare the resulting ensemble-averaged matter power spectrum against the high-fidelity Quijote simulation suite. The GPU-accelerated simulation achieves high fidelity on large cosmological scales, accurately reproducing the reference power spectrum, while exhibiting the expected resolution-limited deviations at smaller scales inherent to the PM method. Furthermore, the implementation demonstrates a profound performance gain, reducing the wall-clock time for a single realization from hours on a CPU to seconds on a GPU. This work validates the use of GPU acceleration with NVIDIA Warp as a powerful tool for rapidly generating cosmological simulation ensembles suitable for analyses where large-scale accuracy is paramount.