Geršgorin Discs and Geometric Multiplicity
نویسندگان
چکیده
If A is an nxn complex matrix and λ is an eigenvalue of A with geometric multiplicity k, then λ is in at least k of the Geršgorin discs Di of A. Let k, r, t be positive integers with k ≤ r ≤ t . Then there is a t x t complex matrix A and an eigenvalue λ of A such that λ has geometric multiplicity k and algebraic multiplicity t, and λ is in precisely r Geršgorin Discs of A. Some examples and related results are also provided. INDEX WORDS: G-discs GERŠGORIN DISCS AND GEOMETRIC MULTIPLICITY
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