## Tzanio KolevEmail: kolev1@llnl.gov
Phone: 925-423-9797 Mailing address:
Tzanio Kolev Lawrence Livermore National Laboratory Box 808, L-560 Livermore, CA 94551-0808 |

Tzanio Kolev is a computational mathematician at the Center for Applied Scientific Computing, where he works on finite element discretizations and solvers for problems arising in various application areas, such as computational electromagnetics, elasticity and compressible shock hydrodynamics. He is a member of the Scalable Linear Solvers (hypre) project, and the project leader of the High-Order Curvilinear Finite Elements for Shock Hydrodynamics (BLAST) project.

Tzanio's research interests include the development and analysis of massively parallel preconditioners, discretization-enhanced algebraic multigrid algorithms, and advanced finite element discretization methods.

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.

## Software

Scalable Linear Solvers |
High-order Shock Hydrodynamics |

Scalable Finite Element Library |
OpenGL Visualization |

## Publications (see also **Google Citations**)

R. Anderson V. Dobrev, Tz. Kolev and R. Rieben, Monotonicity in High-Order Curvilinear Finite Element ALE Remap , submitted to International Journal for Numerical Methods in Fluids, 2014.

LLNL-JRNL-651254

R. Falgout, S. Friedhoff, Tz. Kolev, S. MacLachlan and J. Schroder, Parallel Time Integration with Multigrid,SIAM Journal on Scientific Computing, (submitted) 2013.

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

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

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 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

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.

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.

Updated: 2014-03-21 17:19:04