ϵ-Condition Pseudospectra of the Direct Sum Operators

İsmailov Z., İpek Al P.

LOBACHEVSKII JOURNAL OF MATHEMATICS, cilt.43, ss.3161-3166, 2022 (ESCI) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 43
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1134/s1995080222140141
  • Dergi Adı: LOBACHEVSKII JOURNAL OF MATHEMATICS
  • Derginin Tarandığı İndeksler: Emerging Sources Citation Index (ESCI), Scopus, zbMATH
  • Sayfa Sayıları: ss.3161-3166
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

In this paper, the relationships between e-condition pseudospectrum and e-condition pseudospectral radius of the direct sum of bounded operators in the direct sum of Banach spaces and its coordinate operators are researched. In general case, it is proved that the combination of e-condition pseudospectra of the coordinate operators is a subset of the e-condition pseudospectrum of the direct sum of coordinate operators. In one special case, the state of equality is shown to be valid. Also, an evolution formula is given for e-condition pseudospectral radius of the direct sum of Banach space bounded operators.