Gerschgorin circle theorem

The next result is also general and, while the conditions are not often met, it is an important tool when it can be applied. The theorem is called the Gerschgorin circle theorem. An excellent general reference on matrices is Lancaster and Tismenetsky [LT], and most of the results here are quoted from that source. Another important source is Berman and Plem-mons [BP], particularly for special results on nonnegative matrices. 

For a general Jacobian matiix pertaining to C components and N theoretical trays, as shown by Distefano [Am. Jnst. Chem. Eng. J., 14, 946 (1968)]. Gerschgorin s circle theorem (Varga, Matrix Iterative Analysis, Prentice Hall, Englewood Cliffs, N.J., 1962) may be employed to obtain bounds on the maximum and minimum absolute eigenvalues. Accord-... 

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