This special issue deals with problems related to unit roots and structural change, and the interplay between the two. The research agenda dealing with these topics have proven to be of importance for devising procedures that are reliable for inference and forecasting. Several important contributions have been made. Still, there is scope for improvements and analyses of the properties of existi...

Let a be a mixing topological Markov shift, À a weak Perron number, q(t) a polynomial with nonnegative integer coefficients, and r a nonnegative rational. We construct a homeomorphism commuting with o whose topological entropy is \o%\q(\)q(l/\)}r. These values are shown to include the logarithms of all weak Perron numbers, and are dense in the nonnegative reals.

We study the distribution modulo m of the convergents associated with the d-dimensional Jacobi-Perron algorithm for a.e. real numbers in (0, 1) by proving the ergodicity of a skew product of the Jacobi-Perron transformation; this skew product was initially introdued in [6] for regular continued fractions.

In this paper, we present some lower bounds for the Perron root of a symmetric nonnegative matrix, which are then applied to give the lower bounds of the Perron root of a general nonnegative matrix. These bounds improve the corresponding ones in [3] and [5]. Numerical examples are supplemented to illustrate the effectiveness of the presented bounds. Mathematics subject classification (2010): 15...

Keywords: Delay equations Exponential stability Oscillating coefficient Bohl–Perron type theorem a b s t r a c t New explicit exponential stability conditions are obtained for the nonautonomous linear equation ˙ x(t) + a(t)x(h(t)) = 0, where h(t) ≤ t and a(t) is an oscillating function. We apply the comparison method based on the Bohl–Perron type theorem. Coefficients and delays are not assumed...

The models of collective decision-making considered in this paper are nonlinear interconnected cooperative systems with saturating interactions. These systems encode the possible outcomes of a decision process into different steady states of the dynamics. In particular, they are characterized by two main attractors in the positive and negative orthant, representing two choices of agreement amon...