The advent of a new generation of large-scale galaxy surveys is pushing cosmological numerical simulations in an uncharted territory. The simultaneous requirements of high resolution and very large volume pose serious technical challenges, due to their computational and data storage demand. In this paper, we present a novel approach dubbed Dynamic Zoom Simulations -- or DZS -- developed to tackle these issues. Our method is tailored to the production of lightcone outputs from N-body numerical simulations, which allow for a more efficient storage and post-processing compared to standard comoving snapshots, and more directly mimic the format of survey data. In DZS, the resolution of the simulation is dynamically decreased outside the lightcone surface, reducing the computational work load, while simultaneously preserving the accuracy inside the lightcone and the large-scale gravitational field. We show that our approach can achieve virtually identical results to traditional simulations at half of the computational cost for our largest box. We also forecast this speedup to increase up to a factor of 5 for larger and/or higher-resolution simulations. We assess the accuracy of the numerical integration by comparing pairs of identical simulations run with and without DZS. Deviations in the lightcone halo mass function, in the sky-projected lightcone, and in the 3D matter lightcone always remain below 0.1%. In summary, our results indicate that the DZS technique may provide a highly-valuable tool to address the technical challenges that will characterise the next generation of large-scale cosmological simulations.

中文翻译：

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动态缩放模拟：一种用于模拟光锥的快速自适应算法

新一代大规模星系调查的出现正在推动一个未知领域的宇宙学数值模拟。由于其计算和数据存储需求，同时要求高分辨率和超大体积带来了严峻的技术挑战。在本文中，我们提出了一种称为动态缩放模拟（或 DZS）的新方法，旨在解决这些问题。我们的方法专为从 N 体数值模拟中产生光锥输出而量身定制，与标准联动快照相比，它允许更有效的存储和后处理，并且更直接地模拟调查数据的格式。在DZS中，模拟的分辨率在光锥面外动态降低，减少了计算工作量，同时保持光锥内部和大尺度引力场的精度。我们表明，对于我们最大的盒子，我们的方法可以以一半的计算成本获得与传统模拟几乎相同的结果。我们还预测，对于更大和/或更高分辨率的模拟，这种加速将增加到 5 倍。我们通过比较使用和不使用 DZS 运行的相同模拟对来评估数值积分的准确性。光锥晕质量函数、天空投影光锥和 3D 物质光锥的偏差始终保持在 0.1% 以下。总之，我们的结果表明，DZS 技术可以提供一种非常有价值的工具来解决将表征下一代大规模宇宙学模拟的技术挑战。