Geršgorin and his circles

摘要: This book studies the original results, and their extensions, of Russian mathematician, S.A. Gersgorin, who wrote a seminal paper in 1931, on how to easily obtain estimates all n eigenvalues (characteristic values) any given n-by-n complex matrix. Since publication this paper, there has been many newer results spawned by his will be first which is devoted solely resulting area. As such, it include latest research such as Brauer ovals Cassini Brualdi lemniscates, comparisons. dedicated late Olga Taussky-Todd her husband, John Todd. It was brought light Gersgorin's its significance mathematical world. The level requires only modest background linear algebra analysis, therefore comprehensible upper-level graduate students mathematics.