Alternative characterizations of some linear combinations of an idempotent matrix and a tripotent matrix that commute

Öz

In this work, first, Theorem 2 in [1] [Yao, H., Sun, Y., Xu, C., and Bu, C., A note on linear combinations of an idempotent matrix and a tripotent matrix, J. Appl. Math. Informatics, 27 (5-6), 1493-1499, 2009] and Theorem 2.2 in [2][Özdemir H., Sarduvan M., Özban A.Y., Güler N., On idempotency and tripotency of linear combinations of two commuting tripotent matrices, Appl. Math. Comput., 207 (1), 197-201, 2009] are reconsidered in different ways under the condition that the matrices involved in the linear combination are commutative. Thus, it is seen that there are some missing results in Theorem 2 in [1]. Then, by considering the obtained results and doing some detailed investigations, it is given a new characterization, without any restriction on the involved matrices except for commutativity, of a linear combination of an idempotent and a tripotent matrix that commute.

Anahtar Kelimeler

• Idempotent matrix,tripotent matrix,linear combination,commutativity

Değişmeli bir idempotent ve bir tripotent matrisin bazı lineer kombinasyonlarının alternatif karakterizasyonları

Öz

Bu çalışmada ilk olarak [1][Yao, H., Sun, Y., Xu, C., and Bu, C., A note on linear combinations of an idempotent matrix and a tripotent matrix, J. Appl. Math. Informatics, 27 (5-6), 1493-1499, 2009]’deki Teorem 2 ve [2]([Özdemir H., Sarduvan M., Özban A.Y., Güler N., On idempotency and tripotency of linear combinations of two commuting tripotent matrices, Appl. Math. Comput., 207 (1), 197-201, 2009]’deki Teorem 2.2, lineer kombinasyonda içerilen matrislerin değişmeli olması koşulu altında farklı tarzlarda yeniden ele alınmaktadır. Böylece, [1]’deki Teorem 2’de bazı eksik sonuçların mevcut olduğu görülmüştür. Daha sonra elde edilen sonuçları göz önüne alarak ve bazı detaylı incelemeler yaparak, değişmeli bir idempotent ve bir tripotent matrisin bir lineer kombinasyonunun, içerilen matrisler üzerinde değişmelilik dışında herhangi bir kısıtlama olmaksızın, yeni bir karakterizasyonu verilmektedir.

Anahtar Kelimeler

• İdempotent matris,tripotent matris,lineer kombinasyon,değişmelilik

Kaynakça

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