JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) ›› 2024, Vol. 59 ›› Issue (12): 102-108.doi: 10.6040/j.issn.1671-9352.0.2023.201

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Spectrum and norm of the combinations of two orthogonal projections

MA Nan, LI Yuan*   

  1. School of Mathematics and Statistics, Shaanxi Normal University, Xian 710119, Shaanxi, China
  • Published:2024-12-12

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Abstract: The paper mainly uses Halmos decomposition to investigate the spectrum and norm of the combinations of two orthogonal projections P and Q. The norm of sum and difference of(PQ)n and(QP)n is generalized,and some related results of the spectrum of αP+βQ and the norm of I+αPQ are obtained.

Key words: orthogonal projection, Halmos decomposition, norm, spectrum

CLC Number: 

  • O177.1
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