A characterization of the spread of a normal matrix is used to derive several simple lower bounds for the spread. Comparisons are then made with several known bounds. © 1985.
Johnson, C. R., Kumar, R., & Wolkowicz, H. (1985). Lower bounds for the spread of a matrix. Linear Algebra and Its Applications, 71(C), 161–173. https://doi.org/10.1016/0024-3795(85)90244-7