  The main result is Corollary 2.9 which provides upper bounds on, and even
better, approximates the largest non-trivial eigenvalue in absolute value of
real constant row-sum matrices by the use of vector norm based ergodicity
coefficients Tp. If the constant row-sum matrix is nonsingular, then it is also
shown how its smallest non-trivial eigenvalue in absolute value can be bounded
by using Tp. In the last section, these two results are applied to bound the
spectral radius of the Laplacian matrix as well as the algebraic connectivity
of its associated graph. Many other results are obtained. In particular,
Theorem 2.15 is a convergence theorem for Tp and Theorem 4.7 compares some
ergodicity coefficients to each other.
