On stable exponential cosmological solutions with non-static volume factor in the Einstein-Gauss-Bonnet model

A (n + 1)-dimensional gravitational model with cosmological constant and Gauss Bonnet term is studied. The ansatz with diagonal cosmological metrics is adopted and solutions with exponential dependence of scale factors: a(i) similar to exp (v(i)t), i = 1,...,n, are considered. The stability analysis of the solutions with non-static volume factor is presented. We show that the solutions with v(1) = v(2) = v(3) = H > 0 and small enough variation of the effective gravitational constant G are stable if certain restriction on (v(i)) is obeyed. New examples of stable exponential solutions with zero variation of G in dimensions D = 1 + m + 2 with m > 2 are presented.