Tzanio Kolev is a computational mathematician at the Center for Applied Scientific Computing, where he works on efficient finite element discretizations and solvers for problems arising in various application areas, such as compressible shock hydrodynamics, multi-material ALE simulations, radiation-hydrodynamics and computational electromagnetics.

Tzanio is the director of the Center for Efficient Exascale Discretizations, a co-design center in the Exascale Computing Project. He is also the project leader of the MFEM finite element library, and the High-Order Curvilinear Finite Elements for Shock Hydrodynamics (BLAST) and the Enabling Technologies for High-Order Simulations (ETHOS) projects. He was formerly a member of the Scalable Linear Solvers (hypre) and the Parallel Time Integration with Multigrid (XBraid) projects. 

Tzanio's research interests include the development and analysis of advanced finite element discretization methods, massively parallel preconditioners, discretization-enhanced algebraic multigrid algorithms, and the design and implementation of large-scale scientific software. He joined Lawrence Livermore National Laboratory in 2004 after earning a Ph.D. in Mathematics from Texas A&M University. His dissertation was on least-squares methods for electromagnetic problems.

Projects

• CEED: High-Order Exascale Discretizations
• MFEM: Scalable Finite Elements
• BLAST: High-Order Shock Hydrodynamics
• ETHOS: High-Order Mesh Optimization
• FASTMath: SciDAC Institute
• RF-SciDAC: Tokamak Simulations
• xSDK: Extreme-scale Scientific Software Development Kit
• RADIUSS: LLNL's Rapid Software Development Kit
• GLVis: Finite Element Visualization
• Hypre: Scalable Linear Solvers
• XBraid: Parallel Time Integration

Service

• Editorial board for the SIAM Journal on Scientific Computing.
• PSAAP III review team.

News

• FEM@LLNL seminar series starting. (Jan, 2022)
• New MFEM page with recorded talks and videos. (Nov, 2021)
• Inaugural MFEM Community Workshop. (Oct, 2021)
• MFEM version 4.3 released. (Jul, 2021)
• MFEM featured on S&TR magazine cover. (Apr, 2021)
• GLVis version 4.0 released. (Dec, 2020)
• MFEM version 4.2 released. (Oct, 2020)
• MFEM selected as R&D100 finalist (Sep, 2020)
• Oden Institute seminar (Sep, 2020)
• MFEM overview paper, MFEM: A modular finite element methods library, published in Computers & Mathematics with Applications. Also available on arXiv:1911.09220. (Jul, 2020)
• Video, MFEM: Advanced Simulation Algorithms for HPC Applications, on LLNL's YouTube channel. (Jun, 2020)
• ECP podcast: Major update of the MFEM finite element library broadens GPU support. (Jun, 2020)
• Will Pazner's work on matrix-free high-order solvers highlighted in CASC Newsletter #9. (Jun, 2020)
• MFEM version 4.1 released. (Mar, 2020)
• Remhos a new miniapp for high-order DG remap released. (Mar, 2020)
• Laghos v3.0 released with direct device support based on MFEM-4.1. (Mar, 2020)
• CEED v3.0 and libCEED v0.6 released. (Mar, 2020)
• ECP podcast: Helping applications use future architectures with first-rate discretization libraries. (Feb, 2020)
• Pleanary talk at the 28th International Meshing Roundtable. (Oct, 2019)
• PC magazine article highlighting supercomputing at LLNL. (Jul 2019)
• ECP article: CEED’S Impact On Exascale Computing Project (ECP) Efforts Is Wide-Ranging. (Jul 2019)
• Plenary talk at the inaugural North American High Order Methods Conference (Jun, 2019)
• MFEM version 4.0 released with initial GPU support. (May, 2019)
• AMR and TMOP papers available on arXiv. (May, 2019)
• CEED v2.0 and libCEED v0.4 released with MFEM support. (Mar, 2019)
• A version of the Laghos miniapp released for use in the second edition of the Commodity Technology Systems procurement process. (Mar, 2019)
• Laghos v2.0 released with CUDA, RAJA, OCCA and AMR versions. (Nov, 2018)
• MFEM part of the first release of the Extreme-Scale Scientific Software Stack (E4S) by the Software Technologies focus area of the ECP. (Nov, 2018)
• Unstructured technologies presentation at ATPESC18. (Aug, 2018)
• DEIXIS article about CEED: Scaling the Unknown. (Jul 2018)
• Keynote presentation at European Seminar on Computing, ESCO2018. (Jun 2018)
• MFEM version 3.4 released. (May, 2018)
• MFEM part of OpenHPC, a Linux Foundation project for software components required to deploy and manage HPC Linux clusters. (Apr, 2018)
• CEED v1.0 and libCEED v0.2 released with MFEM support. (Mar, 2018)
• MFEM highlighted in LLNL's Science & Technology Review magazine, including on the cover. (Mar, 2018)
• GCN article: "Exascale a 'main priority' for DOE". (Jan, 2018)
• Initial version of libCEED the low-level CEED API released. (Dec, 2017)
• MFEM version 3.3.2 released. (Nov, 2017)
• MFEM joined the Extreme-scale Scientific Software Development Kit, xSDK. (Nov, 2017)
• Laghos miniapp part of CORAL-2 Benchmarks and ECP’s Proxy Apps Suite. (Nov, 2017)
• Postdoc position available for electromagnetic simulations with MFEM. (Oct, 2017)
• MFEM joined the FASTMath institute in the SciDAC program. (Oct, 2017)
• ECP Highlight: "Co-Design Center Develops Next-Gen Simulation Tools". (Oct, 2017)
• CEED highlighted in CASC Newsletter #3. (Oct, 2017)
• CEED highlighted in LLNL’s 65th Anniversary Book (2017 page). (Oct, 2017)
• News highlight: "LLNL gears up for next generation of computer-aided design and engineering". (Sep, 2017)
• CEED first annual meeting held at LLNL. (Aug, 2017)
• Presentations at ATPESC17. (Aug, 2017)
• Laghos miniapp and CEED benchmarks released. (June, 2017)
• News highlight: "Accelerating Simulation Software with Graphics Processing Units". (May, 2017)
• MFEM version 3.3 and GLVis version 3.3 released. (Jan 28, 2017)
• Newsline: "Lawrence Livermore tapped to lead ‘co-design’ center for exascale computing ecosystem" (Nov 11, 2016)
• Article: "Laying the Groundwork for Extreme-Scale Computing" in Science & Technology Review, see also the YouTube preview (Sep, 2016)
• PyMFEM - a Python wrapper for MFEM by Syun'ichi Shiraiwa from MIT's Plasma Science and Fusion Center released. (Sep 19, 2016)
• MFEM version 3.2 and GLVis version 3.2 released. (Jun 30, 2016)
• New LLNL open-source software Blog and Twitter. (Mar 4, 2016)
• MFEM version 3.1 released. See the interactive documentation. (Feb 16, 2016)
• BLAST and MFEM simulation images in the "Art of Science" exhibition at the Livermore public library. (Feb 5, 2016)
• GLVis version 3.1 released. See the new features. (Feb 5, 2016)
• News highlight: "High-Order Finite Element Library Provides Scientists with Access to Cutting-Edge Algorithms". (Jan 6, 2016)
• MFEM and GLVis repositories moved to GitHub. New websites: mfem.org and glvis.org. (Aug 18, 2015)
• News highlight: "Interweaving Timelines to Save Time". (Apr 13, 2015)
• MFEM version 3.0 released. (Jan 26, 2015)
• GLVis version 3.0 released. (Jan 26, 2015)
• News highlight: "Remapping Algorithm Boosts BLAST Simulations". (Jan 13, 2015)

• Google Scholar
• ResearchGate
• ORCID
• GitHub

Publications hosted at LLNL (no longer updated)

• R. Anderson V. Dobrev, Tz. Kolev and R. Rieben, Monotonicity in High-Order Curvilinear Finite Element ALE Remap, International Journal for Numerical Methods in Fluids, 2014, pp. 249-273. LLNL-JRNL-651254
• R. Falgout, S. Friedhoff, Tz. Kolev, S. MacLachlan and J. Schroder, Parallel Time Integration with Multigrid, SIAM Journal on Scientific Computing, 2014, pp.C635–C661. LLNL-JRNL-645325
• V. Dobrev, Tz. Kolev and R. Rieben, High-order curvilinear finite element methods for elastic-plastic Lagrangian dynamics, Journal of Computational Physics, 2014, pp.1062-1080. LLNL-JRNL-567119
• V. Dobrev, T. Ellis, Tz. Kolev and R. Rieben, High-order curvilinear finite elements for axisymmetric Lagrangian hydrodynamics, Computers and Fluids, 2013, pp.58-69. LLNL-JRNL-521372
• Tz. Kolev and P. Vassilevski, Parallel auxiliary space AMG solver for H(div) problems, SIAM Journal on Scientific Computing, (34) 2012, pp. A3079-A3098. LLNL-JRNL-520391
• Tz. Kolev and P. Vassilevski, Regular decompositions for H(div) spaces, Computational Methods in Applied Mathematics, (12) 2012, pp.437-447. LLNL-JRNL-520451
• V. Dobrev, Tz. Kolev and R. Rieben, High-order curvilinear finite element methods for Lagrangian hydrodynamics, SIAM Journal on Scientific Computing, (34) 2012, pp.B606–B641. LLNL-JRNL-516394
• A.Baker, R. Falgout, Tz. Kolev and U. Yang, Scaling hypre's multigrid solvers to 100,000 cores, High Performance Scientific Computing: Algorithms and Applications - A Tribute to Prof. Ahmed Sameh, M. Berry et al., eds., Springer 2012, pp.261-279. LLNL-JRNL-479591
• A. Baker, R. Falgout, T. Gamblin, Tz. Kolev, M. Schulz, and U. Yang, Scaling algebraic multigrid solvers: on the road to exascale,  Proc. of Competence in High Performance Computing, CiHPC 2010, Schwetzingen Germany, Springer 2012, pp 215-226. LLNL-JRNL-479591
• T. Brunner and Tz. Kolev, Algebraic multigrid for linear systems obtained by explicit element reduction, SIAM Journal on Scientific Computing, (33) 2011, pp.2706-2731. LLNL-JRNL-440891
• A. Baker, R. Falgout, Tz. Kolev and U. Yang, Multigrid smoothers for ultra-parallel computing, SIAM Journal on Scientific Computing, (33) 2011, pp. 2864-2887. LLNL-JRNL-435315
• V. Dobrev, T. Ellis, Tz. Kolev and R. Rieben, Curvilinear finite elements for Lagrangian hydrodynamics, International Journal for Numerical Methods in Fluids, (65) 2011, pp. 1295–1310. LLNL-JRNL-422302
• A. Baker, Tz. Kolev and U. Yang, Improving algebraic multigrid interpolation operators for elasticity problems, Numer. Linear Algebra Appl., (17) 2010, pp. 495-517.
• Tz. Kolev and R. Rieben, A tensor artificial viscosity using a finite element approach, Journal of Computational Physics, (22) 2009, pp. 8336-8366.
• Tz. Kolev and P. Vassilevski, Parallel auxiliary space AMG for H(curl) problems, special issue on “Adaptive and Multilevel Methods in Electromagnetics”, Journal of Computational Mathematics, (27) 2009, pp. 604-623.
• A. Baker, E. Jessup, and Tz. Kolev, A simple strategy for varying the restart parameter in GMRES(m), Journal of Computational and Applied Mathematics, (230) 2009, pp. 751-761.
• Tz. Kolev and P. Vassilevski, Auxiliary space AMG for H(curl) problems, Proceedings of the 17th International Conference on Domain Decomposition Methods, Lecture Notes in Computational Science and Engineering, Springer, 2008, pp.147-154.
• Tz. Kolev, J. Pasciak, and P. Vassilevski, H(curl) auxiliary mesh preconditioning, Numer. Linear Algebra Appl., (15) 2008, pp. 455-471.
• Tz. Kolev and P. Vassilevski, AMG by element agglomeration and constrained energy minimization interpolation, Numer. Linear Algebra Appl., (13) 2006, pp. 771-788.
• J. Bramble, Tz. Kolev and J. Pasciak, A least-squares method for the time-harmonic Maxwell equations, Journal of Numerical Mathematics, (13) 2005, pp. 237-263.
• J. Bramble, Tz. Kolev and J. Pasciak, The approximation of the Maxwell eigenvalue problem using a least-squares method, Math. Comp., (74) 2005, pp. 1575-1598.
• Tz. Kolev and S. Margenov, AMLI preconditioning of pure displacement non-conforming elasticity FEM systems, Proceedings of the Second Conference on Numerical Analysis and Applications, Lecture Notes in Computer Science, Springer, 2001, pp. 482-489.
• Tz. Kolev and S. Margenov, Two-level preconditioning of pure displacement non-conforming FEM systems, Numer. Linear Algebra Appl., (6) 1999, pp. 535-555.

Other documents (no longer updated)

• Scalable multi-physics simulations will require new discretization and numerical methods research, talk at the 2013 DOE Workshop on Applied Mathematics Research for Exascale Computing.
• NNSA Office of Advanced Scientific Computing eNews, March 2013.
• SIAM Computational Science and Engineering (CS&E) logo, 2013.
• NNSA LDRD Symposium, 2011.
• A. Baker, R. Falgout, Tz. Kolev and U. Yang, Multigrid smoothers for ultra-parallel computing: Additional theory and discussion, LLNL Technical Report, 2011. LLNL-JRNL-489114
• LLNL Laboratory Directed Research and Development Annual Report, 2010.
• LLNL Computation Directorate Annual Report, 2010.
• AMG for Linear Systems Obtained by Local Elimination, talk at the 2010 DOE Applied Mathematics Program Meeting.
• T. Ellis, High Order Finite Elements for Lagrangian Computational Fluid Dynamics, Master's Thesis, California Polytechnic State University - San Luis Obispo, 2010.
• Novel solver enables scalable electromagnetic simulations, plenary talk at the SciDAC 2009 conference.
• Top Breakthroughs in Computational Science, SciDAC Review, (11) 2009.
• Report of The Panel on Recent Significant Advancements in Computational Science, 2008.
• LLNL Computation Directorate Annual Report, 2007.
• Linear solutions at hypre speed, 2007.
• Mathematisches Forschungsinstitut Oberwolfach, Report No. 5/2007 on Computational Electromagnetism and Acoustics.
• Tz. Kolev and P. Vassilevski, Parallel eigensolver for H(curl) problems using H1-auxiliary space AMG preconditioning, LLNL Technical Report 226197, 2006.
• Tz. Kolev and P. Vassilevski, Parallel H1-based auxiliary space AMG solver for H(curl) problems, LLNL Technical Report 222763, 2006.
• Tz. Kolev and P. Vassilevski, Some experience with a H1-based auxiliary space AMG for H(curl) problems, LLNL Technical Report 221841, 2006.
• Tz. Kolev, Least-Squares Methods for Computational Electromagnetics, Dissertation, Texas A&M University, 2004.Tz. Kolev, J. Pasciak, and P. Vassilevski, Algebraic construction of mortar finite element spaces with application to parallel AMGe, LLNL Technical Report UCRL-JC-153326, 2003.