Laboratory for Parallel Numerical Algorithms

University of Illinois Urbana-Champaign

Research

We develop algorithms and software for efficient numerical computation, with an emphasis on tensor algebra, matrix computations, and parallel computing.

Tensor algebra

Multidimensional data in scientific computing and machine learning can be represented as tensors. We study dense and sparse tensor algebra, tensor decompositions, and tensor networks, including their algorithms, numerical methods, and software abstractions.

Matrix computations

Numerical linear algebra underlies many computational approaches in the data sciences. We develop fast matrix algorithms for nonlinear optimization, low-rank approximation, and eigenvalue problems.

Quantum systems

Tensor representations provide a way to model quantum entanglement. We investigate parallel numerical algorithms for quantum chemistry, including electronic structure calculations, and for quantum circuit simulation.

Communication-avoiding algorithms

Data movement through memory and across networks constrains performance and scalability. We design parallel algorithms that reduce communication volume and message counts for tensor computations, graph problems, parallel sorting, and bioinformatics.

High-performance numerical libraries

We connect algorithm development with applications through general and scalable parallel library routines.

Research opportunities and contact

For inquiries about research opportunities or collaboration, contact Edgar Solomonik at solomon2@illinois.edu.

Research support

Members

We are part of the scientific computing group at the University of Illinois Urbana-Champaign.

Faculty

Postdoctoral researchers

  • Maryam Dehghan

    Maryam Dehghan

    Postdoctoral Researcher

  • Tong Ding

    Tong Ding

    Postdoctoral Researcher

PhD students

  • Jack Weinstein

    Jack Weinstein

    PhD Student in Computer Science

  • Qizhao Huang

    Qizhao Huang

    PhD Student in Computer Science

  • Zhanrui Zhang

    Zhanrui Zhang

    PhD Student in Computer Science

  • Nick Koskelo

    Nick Koskelo

    PhD Student in Computer Science

Master’s students

  • Akhilesh Mocharla

Undergraduate students

  • Sreehaas Chinnala

Publications

Publications by LPNA members and collaborators.

See also Edgar Solomonik’s complete publication list.

  1. Edgar Solomonik and Markus Bläser.

    Simultaneous matrix multiplication by tensor contraction aggregation.

    arXiv:2610.26563 [math.NA], October 2026.

  2. Navjot Singh, Edgar Solomonik, Xiaoye Sherry Li, and Yang Liu.

    Efficient Tensor Completion Algorithms for Highly Oscillatory Operators.

    Numerical Linear Algebra with Applications 33(4), e70098, 2026.

  3. Yuchen Pang and Edgar Solomonik.

    Simulating Clifford circuits with Gaussian elimination.

    arXiv preprint arXiv:2511.06127, 2025.

  4. Edgar Solomonik.

    Sparse LDL, LU, and inverse butterfly factorization via tree decomposition.

    arXiv preprint arXiv:2504.20305, 2025.

  5. Caleb Ju, Yifan Zhang, and Edgar Solomonik.

    Communication lower bounds for nested bilinear algorithms via rank expansion of Kronecker products.

    Foundations of Computational Mathematics 25(1), 55–101, 2025.

  6. Louis Schatzki, Linjian Ma, Edgar Solomonik, and Eric Chitambar.

    Tensor rank and other multipartite entanglement measures of graph states.

    Physical Review A 110(3), 032409, 2024.

  7. Linjian Ma, Matthew Fishman, Edwin Miles Stoudenmire, and Edgar Solomonik.

    Approximate contraction of arbitrary tensor networks with a flexible and efficient density matrix algorithm.

    Quantum 8, 1580, 2024.

  8. Raghavendra Kanakagiri and Edgar Solomonik.

    Minimum cost loop nests for contraction of a sparse tensor with a tensor network.

    ACM Symposium on Parallelism in Algorithms and Architectures (SPAA), pp. 169–181, June 2024.

  9. Andreas Irmler, Raghavendra Kanakagiri, Sebastian T. Ohlmann, Edgar Solomonik, and Andreas Grüneis.

    Optimizing distributed tensor contractions using node-aware processor grids.

    Lecture Notes in Computer Science, Euro-Par, August 2023.

  10. Caleb Ju, Serif Yesil, Mengyuan Sun, Chandra Chekuri, and Edgar Solomonik.

    Efficient parallel implementation of the multiplicative weight update method for graph-based linear programs.

    arXiv:2307.03307 [cs.DC], July 2023.

  11. Navjot Singh and Edgar Solomonik.

    Alternating Mahalanobis distance minimization for accurate and well-conditioned CP decomposition.

    SIAM Journal on Scientific Computing 45(6), A2781–A2812, 2023.

  12. Edward Hutter and Edgar Solomonik.

    Application performance modeling via tensor completion.

    ACM/IEEE Supercomputing Conference, November 2023.

  13. Wentao Yang, Vipul Harsh, and Edgar Solomonik.

    Optimal round and sample-size complexity for partitioning in parallel sorting.

    ACM Symposium on Parallelism in Algorithms and Architectures, June 2023.

  14. Linjian Ma and Edgar Solomonik.

    Cost-efficient Gaussian tensor network embeddings for tensor-structured inputs.

    Conference on Neural Information Processing Systems, 2022.

  15. Chaoqi Yang, Cheng Qian, Navjot Singh, Cao Xiao, M. Brandon Westover, Edgar Solomonik, and Jimeng Sun.

    ATD: Augmenting CP tensor decomposition by self supervision.

    Conference on Neural Information Processing Systems, 2022.

  16. Samah Karim and Edgar Solomonik.

    Efficient preconditioners for interior point methods via a new Schur-complement-based strategy.

    SIAM Journal on Matrix Analysis and Applications 43(4), 1680–1711, 2022.

  17. Navjot Singh, Zecheng Zhang, Xiaoxiao Wu, Naijing Zhang, Siyuan Zhang, and Edgar Solomonik.

    Distributed-memory tensor completion for generalized loss functions in Python using new sparse tensor kernels.

    Journal of Parallel and Distributed Computing 169, 269–285, 2022.

  18. Linjian Ma and Edgar Solomonik.

    Accelerating alternating least squares for tensor decomposition by pairwise perturbation.

    Numerical Linear Algebra with Applications 29(4), e2431, 2022.

  19. Tim Baer, Raghavendra Kanakagiri, and Edgar Solomonik.

    Parallel minimum spanning forest computation using sparse matrix kernels.

    Proceedings of the SIAM Conference on Parallel Processing for Scientific Computing, February 2022.

  20. Linjian Ma and Edgar Solomonik.

    Fast and accurate randomized algorithms for low-rank tensor decompositions.

    Conference on Neural Information Processing Systems, 2021.

  21. Chaoqi Yang, Navjot Singh, Cao Xiao, Cheng Qian, Edgar Solomonik, Jimeng Sun.

    MTC: Multiresolution tensor completion from partial and coarse observations.

    ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, 2021.

  22. Navjot Singh, Linjian Ma, Hongru Yang, and Edgar Solomonik.

    Comparison of accuracy and scalability of Gauss-Newton and alternating least squares for CP decomposition.

    SIAM Journal on Scientific Computing 43(4), C290–C311, 2021.

  23. Edward Hutter and Edgar Solomonik.

    Accelerating distributed-memory autotuning via statistical analysis of execution paths.

    IEEE International Parallel and Distributed Processing Symposium, May 2021.

  24. Linjian Ma and Edgar Solomonik.

    Efficient parallel CP decomposition with pairwise perturbation and multi-sweep dimension tree.

    IEEE International Parallel and Distributed Processing Symposium, May 2021.

  25. Yuchen Pang, Tianyi Hao, Annika Dugad, Yiqing Zhou, and Edgar Solomonik.

    Efficient 2D tensor network simulation of quantum systems.

    ACM/IEEE Supercomputing Conference, November 2020.

  26. Linjian Ma, Jiayu Ye, and Edgar Solomonik.

    AutoHOOT: Automatic High-Order Optimization for Tensors.

    International Conference on Parallel Architectures and Compilation Techniques, October 2020.

  27. Caleb Ju and Edgar Solomonik.

    Derivation and analysis of fast bilinear algorithms for convolution.

    SIAM Review 62(4), 743–777, 2020.

  28. Yifan Zhang and Edgar Solomonik.

    On stability of tensor networks and canonical forms.

    arXiv:2001.01191 [math.NA], January 2020.

  29. Edward Hutter and Edgar Solomonik.

    Communication-avoiding CholeskyQR2 for rectangular matrices.

    IEEE International Parallel and Distributed Processing Symposium, May 2019.

  30. Tobias Wicky, Edgar Solomonik, and Torsten Hoefler.

    Communication-avoiding parallel algorithms for solving triangular systems of linear equations.

    IEEE International Parallel and Distributed Processing Symposium, 2017.

Alumni and past participants

Postdoctoral researchers

  • Raghavendra Kanakagiri, 2021–2023.

PhD alumni

  • Yuchen Pang (2026)
    Simulating and Analyzing Quantum Computation using Tensor Networks.
  • Navjot Singh (2025)
    Algorithms and software for tensor decompositions.
  • Edward Hutter (2024)
    Accelerated performance modeling and tuning of parallel programs.
  • Linjian Ma (2023)
    Towards efficient algorithms and systems for tensor decompositions and tensor networks.
  • Samah Karim (2022)
    Inexact interior point methods for constrained convex quadratic optimization problems.

Master’s theses

  • Wentao Yang (2022)
    Optimal round and sample-size complexity for partitioning in parallel sorting.
  • Navjot Singh (2020)
    Parallel Gauss-Newton method for CP decomposition.
  • Tobias Wicky (2017)
    A communication-avoiding algorithm for solving linear systems of equations with selective inversion.

Bachelor’s theses

Yiqing Zhou (2020), Tianyi Hao (2020), Youcef Hadjarab (2020), Zecheng Zhang (2019), Pavle Simonovic (2018), and Edward Hutter (2017).

Other past participants

Former graduate and undergraduate researchers and visitors.

  • Jessica Williams
  • Sreevardhan Atyam (CS and Physics)
  • Aniket Deshpande (Physics)
  • Anitej Chanda (CS)
  • Boyang Li (CS & Math)
  • Aarnav Varanasi (Physics)
  • Chandani Grover (CS), 2024–2025
  • Bangyan Shi (CS), 2023–2024
  • Aniruddha Sen (visiting from UMass), summer 2023
  • Mengyuan (Mina) Sun (CS), 2021–2023
  • Changsheng Chen (CS), 2021–2023
  • Tim Baer (CS), 2019–2022
  • Raul Platero (CS), 2017–2021
  • Dipro Ray (CS), 2019–2021
  • Annika Dugad (academic visitor), 2019–2020
  • Caleb Ju (CS), 2018–2020
  • Yifan Zhang (Math, Engineering Physics, and Statistics), 2019–2020
  • Zhaoyu Wu (CS), 2018–2019
  • Hung Woei Neoh (Math & CS), 2018–2019
  • Hongru Yang (CS & Statistics), 2018–2019
  • Yunxin (David) Zhang (CS), 2018–2019
  • Xiaoxiao Wu, 2018–2019
  • Siyuan Zhang, 2018–2019
  • Naijing Zhang, 2017–2019
  • Fan Huang, 2018
  • Eric Song, 2018
  • Ruiqian Yao, 2018
  • Eduardo Yap, 2018
  • Peter Tatkowski, 2018
  • Qile Zhi, 2017
  • Thomas Warther, 2017

Courses and recorded lectures

Recent courses

Lecture and course archive