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two upper bounds on the 𝐴α-spectral radius of a connected graph
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نویسنده
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pirzada shariefuddin
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منبع
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communications in combinatorics and optimization - 2022 - دوره : 7 - شماره : 1 - صفحه:53 -57
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چکیده
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If 𝐴(𝐺) and 𝐷(𝐺) are respectively the adjacency matrix and the diagonal matrix of vertex degrees of a connected graph 𝐺, the generalized adjacency matrix 𝐴α(𝐺) is defined as 𝐴α(𝐺)=α 𝐷(𝐺)+(1-α) 𝐴(𝐺) , where 0≤α≤1. the aα (or generalized) spectral radius λ(aα(g)) (or simply λα) is the largest eigenvalue of aα(g). in this paper, we show that √λα≤α δ+(1−α)2m(1−1ω)where m, δ and ω=ω(g) are respectively the size, the largest degree and the clique number of 𝐺. further, if 𝐺 has order 𝑛 , then we show that √λα d𝑖+ α^2 𝑑𝑖^ 2+4m𝑖(1α)[α+(1α)m𝑖 where 𝑑𝑖 and 𝑚𝑖 are respectively the degree and the average 2degree of the vertex 𝑣𝑖 .
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کلیدواژه
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adjacency matrix ,generalized adjacency matrix ,spectral radius ,clique number
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آدرس
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university of kashmir, department of mathematics, india
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پست الکترونیکی
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pirzadasd@kashmiruniversity.ac.in
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Authors
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