# Andrii Dmytryshyn

**Position:**Senior Lecturer

**School/office:**School of Science and Technology

**Email: **
andrii.dmytryshyn@oru.se

**Phone: **
+46 19 303554

**Room: **
T2121

## About Andrii Dmytryshyn

Andrii's research interests are in the fields of matrix analysis and computational mathematics. Before starting as an Associate Senior Lecturer at Örebro University, Andrii worked and studied in Umeå (Sweden), Bordeaux (France), Padua (Italy), and Kyiv (Ukraine).

Andrii received the SIAM Student Paper Prize 2015 (which is one of the major prizes awarded by the Society for Industrial and Applied Mathematics). He was selected as one of the top 7 candidates for the Householder Prize XX (The Householder Prize is an award for the best dissertation in numerical linear algebra in a 3-year period). Andrii was also an LAA Early Career Speaker at ILAS 2017 and invited and plenary speaker at several other conferences. Dmytryshyn is "Docent in Mathematics" since 2022.

As a principal investigator or sole applicant, Dmytryshyn received a number of grants from STINT, Umeå University, the Kempe foundations, Stiftelsen Längmanska kulturfonden, SIAM, WASP (grant for a PhD student), Wenner-Gren Foundations (grant for a postdoc), Carl Tryggers Foundation (grant for a postdoc), Örebry University, and the Swedish Research Council (VR).

Supervision of research projects at Örebry University:

PhD Projects (main supervisor):

– Sweta Das, since October 2022.

Postdoc Projects (main supervisor):

– Souad Mohaoui, since 2023.

– Massimiliano Fasi, 2020–2021.

Andrii teaches courses on numerical methods for differential equations, applied mathematics, mathematical control theory, matrix computations, and case studies in computational mathematics.

## Research projects

### Active projects

- Data completion problems for motion capture systems
- Eigenstructures of LOw-RAnk matrix polynomials (ELORA)
- Low-rank methods for systems of Sylvester-type matrix equations
- Stochastic simulations of partial differential equations

### Completed projects

## Research groups

## Publications

## Articles in journals

- De Terán, F. , Dmytryshyn, A.
& Dopico, F. M. (2024). Generic Eigenstructures of Hermitian Pencils.
*SIAM Journal on Matrix Analysis and Applications, 45 (1), 260-283.* - Rousse, F. , Fasi, M. , Dmytryshyn, A. , Gulliksson, M.
& Ögren, M. (2024). Simulations of quantum dynamics with fermionic phase-space representations using numerical matrix factorizations as stochastic gauges.
*Journal of Physics A: Mathematical and Theoretical, 57 (1).* - Dmytryshyn, A. (2023). Schur decomposition of several matrices.
*Linear and multilinear algebra.* - Dmytryshyn, A. (2022). Recovering a perturbation of a matrix polynomial from a perturbation of its first companion linearization.
*BIT Numerical Mathematics (62), 69-88.* - Dmytryshyn, A. , Fasi, M.
& Gulliksson, M. (2022). The dynamical functional particle method for multi-term linear matrix equations.
*Applied Mathematics and Computation, 435.* - De Teran, F. , Dmytryshyn, A.
& Dopico, F. (2020). Generic symmetric matrix pencils with bounded rank.
*Journal of Spectral Theory, 10 (3), 905-926.* - De Teran, F. , Dmytryshyn, A.
& Dopico, F. M. (2020). Generic symmetric matrix polynomials with bounded rank and fixed odd grade.
*SIAM Journal on Matrix Analysis and Applications, 41 (3), 1033-1058.* - Dmytryshyn, A. , Johansson, S. , Kågström, B.
& Van Dooren, P. (2020). Geometry of Matrix Polynomial Spaces.
*Foundations of Computational Mathematics, 20 (3), 423-450.* - Dmytryshyn, A. (2019). Miniversal deformations of pairs of symmetric matrices under congruence.
*Linear Algebra and its Applications, 568, 84-105.* - Dmytryshyn, A.
& Dopico, F. M. (2018). Generic skew-symmetric matrix polynomials with fixed rank and fixed odd grade.
*Linear Algebra and its Applications, 536, 1-18.* - Dmytryshyn, A. , Johansson, S.
& Kågström, B. (2017). Canonical structure transitions of system pencils.
*SIAM Journal on Matrix Analysis and Applications, 38 (4), 1249-1267.* - Dmytryshyn, A. , Futorny, V. , Klymchuk, T.
& Sergeichuk, V. V. (2017). Generalization of Roth's solvability criteria to systems of matrix equations.
*Linear Algebra and its Applications, 527, 294-302.* - Dmytryshyn, A.
& Dopico, F. M. (2017). Generic complete eigenstructures for sets of matrix polynomials with bounded rank and degree.
*Linear Algebra and its Applications, 535, 213-230.* - Dmytryshyn, A. (2017). Structure preserving stratification of skew-symmetric matrix polynomials.
*Linear Algebra and its Applications, 532, 266-286.* - Dmytryshyn, A. , Fonseca, C.
& Rybalkina, T. (2016). Classification of pairs of linear mappings between two vector spaces and between their quotient space and subspace.
*Linear Algebra and its Applications, 509, 228-246.* - Dmytryshyn, A. (2016). Miniversal deformations of pairs of skew-symmetric matrices under congruence.
*Linear Algebra and its Applications, 506, 506-534.* - Dmytryshyn, A. , Futorny, V. , Kågström, B. , Klimenko, L.
& Sergeichuk, V. (2015). Change of the congruence canonical form of 2-by-2 and 3-by-3 matrices under perturbations and bundles of matrices under congruence.
*Linear Algebra and its Applications, 469, 305-334.* - Dmytryshyn, A.
& Kågström, B. (2015). Coupled Sylvester-type Matrix Equations and Block Diagonalization.
*SIAM Journal on Matrix Analysis and Applications, 36 (2), 580-593.* - Dmytryshyn, A. , Futorny, V.
& Sergeichuk, V. (2014). Miniversal deformations of matrices under *congruence and reducing transformations.
*Linear Algebra and its Applications, 446 (April), 388-420.* - Dmytryshyn, A.
& Kågström, B. (2014). Orbit closure hierarchies of skew-symmetric matrix pencils.
*SIAM Journal on Matrix Analysis and Applications, 35 (4), 1429-1443.* - Dmytryshyn, A. , Kågström, B.
& Sergeichuk, V. V. (2014). Symmetric matrix pencils: codimension counts and the solution of a pair of matrix equations.
*The Electronic Journal of Linear Algebra, 27, 1-18.* - Dmytryshyn, A. , Kågström, B.
& Sergeichuk, V. V. (2013). Skew-symmetric matrix pencils: codimension counts and the solution of a pair of matrix equations.
*Linear Algebra and its Applications, 438 (8), 3375-3396.* - Dmytryshyn, A. , Futorny, V.
& Sergeichuk, V. (2012). Miniversal deformations of matrices of bilinear forms.
*Linear Algebra and its Applications, 436 (7), 2670-2700.* - Belitskii, G. , Dmytryshyn, A. , Lipyanski, R. , Sergeichuk, V.
& Tsurkov, A. (2009). Problems of classifying associative or Lie algebras over a field of characteristic not 2 and finite metabelian groups are wild.
*The Electronic Journal of Linear Algebra, 18, 516-529.*

## Conference papers

- Ivanyuk-Skulskiy, B. , Kriukova, G.
& Dmytryshyn, A. (2020). Geometric properties of adversarial images.
In:
*Proceedings of the 2020 IEEE Third International Conference on Data Stream Mining & Processing (DSMP).**Paper presented at 3rd International Conference on Data Stream Mining & Processing (DSMP), Lviv, Ukraine, August 21-25, 2020. (pp. 227-230).*IEEE.

## Doctoral theses, comprehensive summaries

- Dmytryshyn, A. (2015). Tools for Structured Matrix Computations: Stratifications and Coupled Sylvester Equations. (Doctoral dissertation). (Comprehensive summary) Umeå: Umeå universitet.

## Licentiate theses, comprehensive summaries

- Dmytryshyn, A. (2014). Skew-symmetric matrix pencils: stratification theory and tools. Lic. (Comprehensive summary) Umeå: Umeå universitet.

## Reports

- Dmytryshyn, A. & Dopico, F. M. (2016). Generic matrix polynomials with fixed rank and fixed degree. Umeå: Umeå Universitet (UMINF 16/19).
- Dmytryshyn, A. , Johansson, S. & Kågström, B. (2015). Canonical structure transitions of system pencils. Umeå: Umeå universitet (UMINF 5).
- Dmytryshyn, A. , Johansson, S. , Kågström, B. & Van Dooren, P. (2015). Geometry of spaces for matrix polynomial Fiedler linearizations. Umeå: Umeå universitet (UMINF 15/17).
- Dmytryshyn, A. (2015). Structure preserving stratification of skew-symmetric matrix polynomials. Umeå: Umeå universitet.
- Dmytryshyn, A. & Kågström, B. (2014). Orbit closure hierarchies of skew-symmetric matrix pencils. Umeå: Umeå universitet (UMINF 14/02).
- Dmytryshyn, A. , Johansson, S. & Kågström, B. (2013). Codimension computations of congruence orbits of matrices, symmetric and skew-symmetric matrix pencils using Matlab. Umeå: Umeå Universitet (UMINF 13/18).