1. On maximal distances in a commuting graphGregor Dolinar, Bojan Kuzma, Polona Oblak, 2012, original scientific article Abstract: It is shown that matrices over algebraically closed fields that are farthest apart in the commuting graph must be non-derogatory. Rank-one matrices and diagonalizable matrices are also characterized in terms of the commuting graph. Keywords: matematika, linearna algebra, teorija grafov, komutirajoči grafi, matrična algebra, algebraično zaprt obseg, centralizator, razdalja v grafih, mathematics, linear algebra, graph theory, commuting graph, matrix algebra, algebraically closed field, centralizer, distance in graphs Published in RUP: 03.04.2017; Views: 2327; Downloads: 256 Link to full text |
2. Norm preservers of Jordan productsBojan Kuzma, Gorazd Lešnjak, Chi-Kwong Li, Tatjana Petek, Leiba Rodman, 2011, original scientific article Abstract: V članku klasificiramo surjektivne preslikave, ki na algebri kompleksnih matrik ohranjajo Frobeniusovo normo Jordanskega produkta. Izkaže se, da so do unitarne podobnosti in množenja s skalarnim večkratnikom vse tovrstne preslikave le štirih možnih tipov: (i) preslikava, ki je lokalno adjungiranje na normalnih matrikah in identiteta izven normalnih matrik, (ii) transponiranje, (iii) kompleksna konjugacija in (iv) adjungiranje. Do podobnih zaključkov pridemo tudi v primeru nekaterih drugih unitarno invariantnih norm, kjer pokažemo, da preslikava bodisi normalne matrike množi s skalarji, bodisi jih adjungira in množi s skalarji. Keywords: matematika, linearna algebra, jordanski produkt, matrična norma, ohranjevalci Published in RUP: 15.10.2013; Views: 3281; Downloads: 228 Link to full text |
3. Fosner, Ajda; Šemrl, Peter: Additive maps on matrix algebras preserving invertibility. (English). - [J] Acta Math. Sin., Engl. Ser. 21, No. 4, 681-684 (2005). [ISSN 1439-8516; ISSN 1439-7617]Bojan Kuzma, 2006, review, book review, critique Keywords: matematika, linearna algebra, aditivna preslikava, ohranjevalec obrnljivosti, ohranjevalec singularnosti, matrična algebra Published in RUP: 15.10.2013; Views: 3690; Downloads: 40 Link to full text |
4. Chebotar, Mikhail A.; Fong, Yuen; Lee, Pjek-Hwee: On maps preserving zeros of the polynomial $xy - yx^ast$. (English). - [J] Linear Algebra Appl. 408, 230-243(2005). [ISSN 0024-3795]Bojan Kuzma, 2006, review, book review, critique Keywords: matematika, linearna algebra, linearni ohranjevalci, funkcijske identitete, matrična algebra Published in RUP: 15.10.2013; Views: 3637; Downloads: 26 Link to full text |