I am an assistant professor in computational mathematics.
Since January 2021 I am assistant professor in computational mathematics at Umeå University. My primary research interest is the development, analysis, and implementation of numerical methods for partial differential equations.
In the past few years, much of my research effort has been devoted to efficient and robust numerical simulation of acoustic and elastic wave propagation, which are modelled by second order hyperbolic partial differential equations. For the numerical solutions, I have considered stable and high-order accurate finite difference and discontinuous Galerkin methods. This topic is still an important part of my current work. For hyperbolic problems, a recent interest is perfectly matched layer (PML) technique to truncate computational domains. Another research interest is multiscale modelling where material properties vary in space on different scales. I have worked on multiscale methods for flows in porous media and look forward to extending the techniques to hyperbolic problems.
Before joining Umeå University I was a lecturer at Mälardalens högskola in 2019-2020, where I taught several courses in mathematics and numerical methods. Before that I was a postdoc at Chalmers University of Technology in 2017-2019 working with Axel Målqvist on multiscale methods for flows in porous media. Prior to Chalmers, I obtained a PhD in scientific computing at Uppsala University with Gunilla Kreiss as advisor. We focused on high-order finite difference discretizations on nonuniform meshes for the wave equation and established error estimates for a class of discretizations in the normal mode analysis framework.
Preprints
[P2] A hybrid numerical method for elastic wave propagation in discontinuous media with complex geometry, Andreas Granath and Siyang Wang, Submitted.
[P1] Perfectly matched layer for the elastic wave equation in layered media, Kenneth Duru, Balaje Kalyanaraman and Siyang Wang, Submitted.
2024
[J19] Upwind summation-by-parts finite differences: error estimates and WENO methodology, Yan Jiang and Siyang Wang, Journal of Scientific Computing, 100 (2024), 75.
2023
[J18] A finite difference - discontinuous Galerkin method for the wave equation in second order form, Siyang Wang and Gunilla Kreiss, SIAM Journal on Numerical Analysis, 60(2023), 1962-1988.
2022
[J17] A conservative and energy stable discontinuous spectral element method for the shifted wave equation in second order form, Kenneth Duru, Siyang Wang and Kenny Wiratama, SIAM Journal on Numerical Analysis, 60(2022), 1631-1664.
[J16] A high order finite difference method for the elastic wave equation in bounded domains with nonconforming interfaces, Lu Zhang and Siyang Wang, SIAM Journal on Numerical Analysis, 60(2022), 1516-1547.
[J15] An energy-based summation-by-parts finite difference method for the wave equation in second order form, Siyang Wang, Daniel Appelö and Gunilla Kreiss, Journal of Scientific Computing, 91 (2022), 52.
2021
[J14] Summation-by-parts approximations of the second derivative: Pseudoinverses and revisitation of a high order accurate operator, Sofia Eriksson and Siyang Wang, SIAM Journal on Numerical Analysis, 59 (2021), 2669-2697.
[J13] Elastic wave propagation in curvilinear coordinates with mesh refinement interfaces by a fourth order finite difference method, Lu Zhang, Siyang Wang and N. Anders Petersson, SIAM Journal on Scientific Computing, 43 (2021), A1472-A1496.
[J12] Numerical upscaling for heterogeneous materials in fractured domains, Fredrik Hellman, Axel Målqvist and Siyang Wang, ESAIM: Mathematical Modelling and Numerical Analysis, 55 (2021), S761-S784.
[J11] Bridging physics-based and equivalent circuit models for lithium-ion batteries, Zeyang Geng, Siyang Wang, Matthew J. Lacey, Daniel Brandell, Torbjörn Thiringer, Electrochimica Acta, 372 (2021) 137829.
2019
[J10] Fourth order finite difference methods for the wave equation with mesh refinement interfaces, Siyang Wang and N. Anders Petersson, SIAM Journal on Scientific Computing, 41 (2019), A3246–A3275.
[J9] Order-preserving interpolation for summation-by-parts operators at nonconforming grid interfaces, Martin Almquist, Siyang Wang, and Jonatan Werpers, SIAM Journal on Scientific Computing, 41 (2019), A1201–A1227.
[J8] An energy‐based discontinuous Galerkin method for coupled elasto‐acoustic wave equations in second‐order form, Daniel Appelö and Siyang Wang, International Journal of Numerical Methods for Engeneering, 119 (2019), 618–638.
2018
[J7] An improved high order finite difference method for non-conforming interfaces for the wave equation, Siyang Wang, Journal of Scientific Computing, 77 (2018), 775-792.
[J6] High-order numerical methods for 2D parabolic problems in single and composite domains, Gustav Ludvigsson, Kyle R. Steffen, Simon Sticko, Siyang Wang, Qing Xia, Yekaterina Epshteyn and Gunilla Kreiss, Journal of Scientific Computing, 76 (2018), 812–847.
[J5] Convergence of finite difference methods for the wave equation in two space dimensions, Siyang Wang, Anna Nissen and Gunilla Kreiss, Mathematics of Computation, 87 (2018), 2737-2763.
2017
[J4] An explicit Hermite-Taylor method for the Schrödinger equation, Daniel Appelö, Gunilla Kreiss and Siyang Wang, Communications in Computational Physics, 21 (2017), 1207-1230.
[J3] Convergence of summation-by-parts finite difference methods for the wave equation, Siyang Wang and Gunilla Kreiss, Journal of Scientific Computing, 71 (2017), 219–245.
2016
[J2] High order finite difference methods for the wave equation with non-conforming grid interfaces, Siyang Wang, Kristoffer Virta and Gunilla Kreiss, Journal of Scientific Computing, 68 (2016), 1002-1028.
2014
[J1] Stochastic reaction-diffusion processes with embedded lower-dimensional structures, Siyang Wang, Johan Elf, Stefan Hellander and Per Lötstedt, Bulletin of mathematical biology, 76 (2014), 819-853.
Thesis
[T1] Finite difference and discontinuous Galerkin methods for wave equations, Siyang Wang, Uppsala University, 2017.
2024
May 28-June 1: Internation Conference on Applied Mathematics, Hong Kong.
2023
Dec 8: Grading committee to Vidar Stiernström's PhD dissertation, Uppsala University, Sweden.
Nov 13-16: MIRAI2.0 workshop, Umeå, Sweden.
Oct 10-12: Swedish e-Science Academy & worshop on numerical linear algebra, Uppsala University, Sweden.
Aug 28 -31: International Symposium on Mathematical Biology, Kyoto, Japan.
Aug 20-25: International Congress of Industrial and Applied Mathematics, Tokyo, Japan.
Aug 14-18: International Conference on Spectral and High Order Methods, Seoul, Korea.
Aug 9-12: The Fifth International Workshop on Development and Application of High-Order Numerical Methods, Qingdao, China.
July 30-Aug 8: Visit University of Science and Technology of China, China.
April 7-16: Visit Kyushu University and University of Tokyo, Japan.
March 27 - March 31: Attend South Africa - Sweden research and innovation week, University of Western Cape, Cape Town, South Africa.
2022
December 2: Opponent to Gustav Eriksson's half-time (Licentiate) seminar, Uppsala University, Uppsala, Sweden.
December 1: Research seminar at Uppsala University, Uppsala, Sweden.
November 12-18: Visit University of Tokyo and attend MIRAI2.0 workshop at Kyushu University, Japan.
May 27 - June 4: Visit Columbia University, NY, USA.
May 6: Research seminar at UMIT, Umeå Uniersity, Umeå, Sweden.
March 21 - April 19: Visit Australian National University, Canberra, Australia.
April 11: Talk at Australian Academy of Science - Elizabeth and Frederick White Research Conference, Canberra, Australia.
April 7: Colloquium at Australian National University, Canberra, Australia.
January 21: Research seminar at Michigan State University (online).
2021
December 2: Research seminar at Royal Institue of Technology, Stockholm, Sweden.
March 15: Research seminar at Australian National University (online).
I have taught courses in mathematics and numerical analysis.
Numerical methods for partial differential equations (21,22,23,24)
Mathematics for economics and business (19,20)
Numerical methods with MATLAB (19,20)
Vector algebra (19)
Finite element methods (20)
Biomathematics and bioinformatics (20)
Numerical analysis (18)
Scientific computing bridging course (13,14,15,16,17)