RUS  ENG
Full version
JOURNALS // Sibirskii Zhurnal Vychislitel'noi Matematiki // Archive

Sib. Zh. Vychisl. Mat., 2021 Volume 24, Number 2, Pages 167–177 (Mi sjvm773)

This article is cited in 1 paper

A rational algorithm for checking the congruence of unitoid matrices

Kh. D. Ikramova, A. M. Nazarib

a Lomonosov Moscow State University, Moscow, Russia
b Arak University, Arak, Islamic Republic of Iran

Abstract: A matrix is said to be unitoid if it can be brought to diagonal form by a congruence transformation. We say that an algorithm is rational if it is finite and uses the arithmetic operations only. There exist rational methods designed for checking congruence of particular classes of unitoid matrices, for example, Hermitian, accretive, or dissipative matrices. We propose a rational algorithm for checking congruence of general unitoid matrices. The algorithm is heuristic in the sense that the user is required to set the values of two integral parameters $M$ and $N$. The choice of these values depends on the available a priori information about the proximity of neighboring canonical angles of the matrices under checking.

Key words: congruence, unitoid matrix (unitoid), cosquare, similarity, Toeplitz decomposition, indices of inertia, Pythagorean triples, Maple, circulants.

UDC: 512.643

Received: 25.02.2020
Revised: 16.07.2020
Accepted: 04.02.2021

DOI: 10.15372/SJNM20210204


 English version:
Numerical Analysis and Applications, 2021, 14:2, 145–154

Bibliographic databases:


© Steklov Math. Inst. of RAS, 2026