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Abstract - Learning Neural Operator Surrogates for the Black Hole Accretion Code
General-relativistic magnetohydrodynamic (GR-MHD) simulations are essential for studying black hole accretion, relativistic jets, and magnetic reconnection, yet their computational cost severely limits systematic parameter exploration. We investigate neural operator surrogates for two astrophysically relevant simulation scenarios produced by the Black Hole Accretion Code (\texttt{BHAC}). First, a Physics Informed Fourier Neural Operator (PINO) is trained on the special-relativistic resistive MHD (SRRMHD) evolution of the Orszag-Tang vortex over a range of resistivities spanning the Sweet-Parker and fast reconnection regimes. By embedding the governing equations as an additional loss term evaluated at finer temporal resolution than the available data supervision, the model learns dynamics at time steps where no simulation data is provided, enabling recovery of plasmoid formation that a data-only baseline trained on the same sparse snapshots fails to reproduce. To our knowledge, the present work is the first application of a physics informed neural operator to special relativistic resistive MHD, and the first to investigate the capability of such models to resolve plasmoid formation in SRRMHD. In a second line of investigation, an OFormer-style Transformer Neural Operator is trained on the evolution of spine-sheath relativistic jets created with \texttt{BHAC}, in special-relativistic MHD (SRMHD). The model is directly applied on the adaptive mesh, highlighting the need for linear attention due to long sequences. The neural surrogate model is capable of capturing most of the major details, especially in early predictions. To our knowledge, this constitutes the first application of a neural operator directly on a high resolution adaptive mesh refinement grid in the context of MHD simulations.
学习用于黑洞吸积代码的神经算子替代模型 /
Learning Neural Operator Surrogates for the Black Hole Accretion Code
1️⃣ 一句话总结
本文提出用两种神经网络替代模型加速黑洞吸积模拟:第一种通过物理信息傅里叶神经算子(PINO)学习磁重联过程,即使训练数据稀疏也能预测出精细的等离子体团结构;第二种采用OFormer式变压器神经算子直接在自适应网格上模拟相对论性喷流演化,显著降低了长序列计算成本,两项工作均是首次将神经算子应用于相关物理过程。