Abstract :
The paper attempts to solve a problem which was called a “challenge for the future” in Linear Algebra Appl. We define and investigate a new quantity for real matrices, the sign-real spectral radius, and derive various characterizations, bounds, and properties of it. In certain aspects our quantity shows similar behavior to the Perron root of a nonnegative matrix. It is shown that our quantity also has intimate connections to the componentwise distance to the nearest singular matrix. Relations to the Perron root of the (entrywise) absolute value of the matrix and to the μ-number are given as well.
