Dr Behnam Hashemi

Before joining the University of Leicester, I worked at Qatar University and Shiraz University of Technology as an associate professor and at the University of Oxford as a postdoc.

My research interests include numerical linear and multilinear algebra, low-rank approximation and self-validated numerical algorithms. During 2014-2017 I worked on the development of Chebfun3, a software package involving 15000 lines of object-oriented MATLAB code for numerical computing with 3D functions defined on a box. I have also worked on matrix theory over ordered semirings. More details about my work can be found at https://sites.google.com/view/bhashemi/research

Here is a list of most of my journal publications.

B. Hashemi, Y. Nakatsukasa, L.N. Trefethen, Rectangular eigenvalue problems, Advances in Computational Mathematics 48, 80 (2022), full text publicly available at https://doi.org/10.1007/s10444-022-09994-8

B. Hashemi, Y. Nakatsukasa, Least-squares spectral methods for ODE eigenvalue problems, SIAM Journal on Scientific Computing 44 (2022) A3244-A3264, https://doi.org/10.1137/21M1445934

B. Hashemi, Sufficient conditions for the solvability of a Sylvester-like absolute value matrix equation, Applied Mathematics Letters 112, 106818 (2021), https://doi.org/10.1016/j.aml.2020.106818

A. Paganini, B. Hashemi, E.A. Ballester, L. Belluzzi, Fast and accurate approximation of the angle-averaged redistribution function for polarized radiation, Astronomy and Astrophysics 645, A4 (2021), full text publicly available at https://doi.org/10.1051/0004-6361/201937149

J.L. Aurentz, B. Hashemi, The Laurent-Horner method for validated evaluation of Chebyshev expansions, Applied Mathematics Letters 102, 106113 (2020), https://doi.org/10.1016/j.aml.2019.106113

A. Frommer, B. Hashemi, Computing enclosures for the matrix exponential, SIAM Journal on Matrix Analysis and Applications 41 (2020) 1674-17037, https://doi.org/10.1137/19M1263431

B. Hashemi, Enclosing Chebyshev expansions in linear time, ACM Transactions on Mathematical Software 45 (2019) 1-33, https://doi.org/10.1145/3319395

B. Hashemi, Y. Nakatsukasa, On the spectral problem for trivariate functions, BIT Numerical Mathematics 58 (2018) 981-1008, full text publicly available at https://doi.org/10.1007/s10543-018-0710-4

B. Hashemi, L.N. Trefethen, Chebfun in three dimensions, SIAM Journal on Scientific Computing 39 (2017) C341-C363, https://doi.org/10.1137/16M1083803

B. Hashemi, H. Tavakolipour, M.N. Shirazi, Explicit formulae for the greatest least-squares and minimum norm g-inverses and the unique group inverse of matrices over commutative residuated dioids, Semigroup Forum 92 (2016) 541-550, full text publicly available at https://doi.org/10.1007/s00233-015-9771-8

B. Hashemi, M.M. Khalilabadi, H. Tavakolipour, A cubic time algorithm for finding the principal solution to Sylvester matrix equations over (max,+), Linear and Multilinear Algebra 63 (2015) 283-295, https://doi.org/10.1080/03081087.2013.860600

B. Hashemi, M.M. Khalilabadi, H. Tavakolipour, On the fixed-point type Sylvester matrix equations over complete commutative dioids, Electronic Journal of Linear Algebra 27 (2014) 882-891, full text publicly available at https://doi.org/10.13001/1081-3810.2864

A. Frommer, B. Hashemi, T. Sablik, Computing enclosures for the inverse square root and the sign function of a matrix, Linear Algebra and its Applications 456 (2014) 199-213, full text publicly available at https://doi.org/10.1016/j.laa.2013.11.047

B. Hashemi, H. Tavakolipour, M.N. Shirazi, Comparison of the quasi-inverses of the Kronecker sum and product of matrices over complete commutative dioids with applications, Linear Algebra and its Applications 448 (2014) 22-36, full text publicly available at https://doi.org/10.1016/j.laa.2014.01.028

A. Frommer, B. Hashemi, Verified stability analysis using the Lyapunov matrix equation, Electronic Transactions on Numerical Analysis 40 (2013) 187-203, full text publicly available at https://etna.ricam.oeaw.ac.at/vol.40.2013/pp187-203.dir/pp187-203.pdf

B. Hashemi, H. Tavakolipour, A non-induced interval matrix norm, Reliable Computing 18 (2013) 144-146, full text publicly available at https://www.cs.utep.edu/interval-comp/reliable-computing-18-pp-144-146.pdf

B. Hashemi, M. Dehghan, The interval Lyapunov matrix equation: Analytical results and an efficient numerical technique for outer estimation of the united solution set, Mathematical and Computer Modelling 55 (2012) 622-633, full text publicly available at https://doi.org/10.1016/j.mcm.2011.08.036

A. Frommer, B. Hashemi, Verified error bounds for solutions of Sylvester matrix equations, Linear Algebra and its Applications 436 (2012) 405-420, full text publicly available at https://doi.org/10.1016/j.laa.2010.12.002

B. Hashemi, M. Dehghan, Results concerning interval linear systems with multiple right-hand sides and the interval matrix equation AX= B, Journal of Computational and Applied Mathematics 235 (2011), 2969-2978, full text publicly available at https://doi.org/10.1016/j.cam.2010.12.015

A. Frommer, B. Hashemi, Verified computation of square roots of a matrix, SIAM Journal on Matrix Analysis and Applications 31 (2010), 1279-1302, https://doi.org/10.1137/090757058

B. Hashemi, M. Dehghan, Efficient computation of enclosures for the exact solvents of a quadratic matrix equation, Electronic Journal of Linear Algebra 20 (2010) 519-536, full text publicly available at https://doi.org/10.13001/1081-3810.1391

M. Dehghan, M. Ghatee, B. Hashemi, Inverse of a fuzzy matrix of fuzzy numbers, International Journal of Computer Mathematics 86 (2009) 1433-1452, https://doi.org/10.1080/00207160701874789

M. Dehghan, B. Hashemi, Determination of the degrees of P-property and nonnegative invertibility for a fuzzy matrix, International Journal of Approximate Reasoning 46 (2007) 98-108, full text publicly available at https://doi.org/10.1016/j.ijar.2006.09.002

I teach MA2042 in Semester 2 of the 2022-2023 academic year.

I am currently serving on the editorial board of the following journals:

• SIAM Journal on Matrix Analysis and Applications (SIMAX), Associate Editor since 2018

• Bulletin of the Iranian Mathematical Society (BIMS), Managing Editor since 2022

My earlier professional service includes the following editorial activities:

• (Numerical Analysis) Section Editor, Bulletin of the Iranian Mathematical Society (BIMS), Oct. 2019 - Jun. 2022
• Member of the editorial board, The Culture and Thought of Mathematics, An expository journal of the Iranian Mathematical Society published in Persian, Oct. 2013 - Sep. 2019
  
  

I am also a Reviewer of the Mathematical Reviews of the American Mathematical Society (AMS).