torch-sla: Differentiable Sparse Linear Algebra with Adjoint Solvers and Sparse Tensor Parallelism for PyTorch

Industrial scientific computing predominantly uses sparse matrices to represent unstructured data -- finite element meshes, graphs, point clouds. We present \torchsla{}, an open-source PyTorch library that enables GPU-accelerated, scalable, and differentiable sparse linear algebra. The library addresses three fundamental challenges: (1) GPU acceleration for sparse linear solves, nonlinear solves (Newton, Picard, Anderson), and eigenvalue computation; (2) Multi-GPU scaling via domain decomposition with halo exchange, reaching \textbf{400 million DOF linear solve on 3 GPUs}; and (3) Adjoint-based differentiation} achieving $\mathcal{O}(1)$ computational graph nodes (for autograd) and $\mathcal{O}(\text{nnz})$ memory -- independent of solver iterations. \torchsla{} supports multiple backends (SciPy, cuDSS, PyTorch-native) and seamlessly integrates with PyTorch autograd for end-to-end differentiable simulations. Code is available at https://github.com/walkerchi/torch-sla.