Hari Sundar portrait
  • Associate Professor, School Of Computing
  • Assistant Professor, School Of Computing


Research Keywords

  • scientific computing
  • Parallel and Distributed Computing
  • Parallel Algorithms
  • Computational Sciences


  • Scalable Space-time adaptivity for Simulations of Binary Black Hole Intermediate-Mass-Ratio-Inspirals, Advances and Challenges in Computational Relativity, ICERM, Brown University. Invited Talk/Keynote, Presented, 09/16/2020.
  • Scalable Space-Time Adaptivity for Simulations of Binary Black Hole Intermediate-Mass-Ratio-Inspirals SIAM PP'20. Invited Talk/Keynote, Presented, 02/13/2020.
  • Scalable Space-time adaptivity for Simulations of Binary Black Hole Intermediate-Mass-Ratio-Inspirals, CS Colloqium, University of Illinois at Urbana-Champagne. Invited Talk/Keynote, Presented, 10/09/2019.
  • Scalable Space-time adaptivity for Simulations of Binary Black Hole Intermediate-Mass-Ratio-Inspirals, Center for Relativistic Astrophysics, Georgia Institute of Technology, Atlanta, GA. Invited Talk/Keynote, Presented, 06/05/2019.
  • A Scalable Framework for Adaptive Computational General Relativity on Heterogeneous Clusters, Oden Institute, University of Texas at Austin, Austin, TX. Invited Talk/Keynote, Presented, 04/25/2019.
  • Scalability & Adaptivity: Achieving Conflicting Goals in a Heterogeneous Computing Era, Mechanical Engineering Seminar, Iowa State University, Ames, IA. Invited Talk/Keynote, Presented, 04/09/2019.
  • dendro-GR: Enabling Adaptivity & Parallelism for Computational Relativity, Computational Challenges in Gravitational Wave Astronomy, IPAM, UCLA . Invited Talk/Keynote, Presented, 02/01/2019.
  • Parallel Fast Gauss Transform, SIAM Parallel Processing for Scientific Computing, Mar 7 2018, Waseda University, Tokyo, Japan. Invited Talk/Keynote, Presented, 03/07/2018.
  • Efficient Parallel Streaming Algorithms for large-scale Inverse Problems - September 13, 2017 - IEEE High Performance Extreme Computing Conference, Waltham, MA. Conference Paper, Refereed, Presented, 09/13/2017.
  • Parallel Algorithms for the Computation of Cycles in Relative Neighborhood Graphs - August 16, 2017 - 46th International Conference on Parallel Processing, Bristol, UK. Conference Paper, Refereed, Presented, 08/16/2017.
  • A Scalable Hierarchical Semi-Separable Library for Heterogeneous Clusters, 46th International Conference on Parallel Processing (ICPP). Conference Paper, Refereed, Presented, 08/16/2017.
  • Machine and Application Aware Partitioning for Adaptive Mesh Refinement Applications, 26th International Symposium on High-Performance Parallel and Distributed Computing, 2017. Conference Paper, Refereed, Presented, 06/12/2017.
  • A Parallel Wavelet Approach for Binary Compact Object Mergers, Hyun Lim, Eric Hirschmann, David Neilsen, William Black, Matthew Anderson, Hari Sundar, Milinda Fernando. Other, Presented, 01/27/2017.
  • H-to-P Efficiently: Solving HDG Systems via AMG Within The Nektar++ Framework, Hari Sundar and Robert Kirby, University of Utah, USA; Spencer Sherwin, Imperial College London, United Kingdom SIAM Annual Meeting, Boston, MA . Invited Talk/Keynote, Presented, 07/11/2016.
  • A Nested Partitioning Algorithm for Adaptive Meshes on Heterogeneous Clusters, 29th ACM on International Conference on Supercomputing, Newport Beach, CA. Conference Paper, Refereed, Presented, 06/23/2015.
  • Parallel hp-Multigrid for HDG, SIAM Conference on Computational Science and Engineering, Salt Lake City, UT Feb 2015. Invited Talk/Keynote, Presented, 02/23/2015.
  • A Nested Partitioning Scheme for Adaptive Meshes on Parallel Heterogeneous Clusters SIAM Conference on Parallel Processing for Scientific Computing, Portland, OR. Other, Presented, 02/20/2014.

Research Groups

  • David van Komen, Graduate Student. 01/18/2021 - present.
  • LeAnn Leslie, Graduate Student. 08/17/2020 - present.
  • Eric Taylor Heisler, Graduate Student. 08/26/2019 - present.
  • Songzhe Xu, Postdoc. 06/03/2019 - present.
  • Bobby King, Undergraduate Student. 01/07/2019 - 12/23/2019.
  • Liam Moynihan, Graduate Student. School of Computing. 01/07/2019 - present.
  • Han Duc Tran, Graduate Student. 08/20/2018 - present.
  • Masado Ishii, Graduate Student. 08/20/2018 - present.
  • Maxx Carlson, Graduate Student. School of Computing. 08/14/2017 - present.
  • Weerahannadige Milinda Shyamala Fernando, Graduate Student. 08/17/2015 - present.
  • Seyed Majid Rasouli-Pichahi, Graduate Student. 08/17/2015 - present.
  • Christopher Mertin, Graduate Student. 08/17/2015 - 07/10/2017.


  • Hindi, fluent.
  • Tamil, fluent.
  • Urdu, fluent.

Software Titles

  • UQ-SKetch. Code to compress simulation data on the fly for UQ problems, thereby making the gradient and Hessian computations more efficient. Release Date: 08/18/2020. Inventors: Liam Moynihan, Milinda Fernando, Hari Sundar.
  • EigenMM: Scalable Generalized Eigensolvers. We present highly scalable generalized eigensolvers for computing the full spectrum of operators, mainly for the purpose of evaluating fractional operators. Release Date: 08/03/2020. Inventors: Max Carlson, Hari Sundar.
  • Dendro-LTS. Package for locally adaptive time-stepping on octree meshes. Release Date: 04/06/2020. Inventors: Milinda Fernando, Hari Sundar.
  • Saena: Scalable Algebraic Multigrid. Saena is an extremely scalable, large-scale AMG solver and preconditioner for solving large elliptic problems. Release Date: 10/15/2018. Inventors: Majid Rasouli, Hari Sundar.
  • DendroGR. A portable, highly-scalable, extensible, and easy-to-use public infrastructure for general relativity simulations that will be forward-compatible with next-generation heterogeneous clusters. The goal of this work is to perform advanced, massively parallel numerical simulations of IMRIs with mass ratios on the order of 1/100 to generate waveforms that can be used in LIGO data analysis and to calibrate approximate methods. Release Date: 07/18/2018. Inventors: Hari Sundar, Milinda Fernando, David Nielsen.
  • esort: energy and power efficient sorting on distributed GPU clusters. The package implements communication avoiding distributed sorting algorithms along with highly optimized GPU sorting routines for node-local sorting. The code is highly tuned and provides parallelism using MPI, OpenMP, CUDA and SIMD vectorization. Release Date: 11/16/2015.
  • homg. High-order finite-element package using hexahedral elements. The code is a testbed for geometric multigrid approaches for high order discretizations. The current implementation supports setting up a combination of h and p heirarchy. The following smoothers are supported, * Jacobi * Chebyshev-accelerated Jacobi * block Jacobi * Symmetric SOR . Release Date: 02/24/2014. Inventors: Hari Sundar.
  • hyksort. Highly scalable distributed sorting and selection library. The package im- plements BitonicSort, MergeSort, SampleSort and HykSort. The code is highly tuned and provides parallelism using MPI, OpenMP and SIMD vectorization. Release Date: 02/02/2014. Inventors: Hari Sundar, Dhairya Malhotra.
  • pfgt. A distributed memory implementation of the fast Gauss Transform. Fast adaptive parallel algorithms to compute the sum of N Gaussians at M points using the fast Gauss Transform. We use parallel octrees and a new scheme for translating the plane-waves to efficiently handle non-uniform distributions. Release Date: 02/15/2011.
  • Dendro. A C++ library for constructing and balancing octrees in parallel. It also generates hexahedral meshes from the octrees and extends PETSc’s distributed ar- ray framework to support octree-based meshing. Basic routines for solving PDEs on such meshes using the finite element method are also provided. Release Date: 03/16/2009. Inventors: Hari Sundar, Rahul Sampath.