POSITIVITY, cilt.22, sa.3, ss.803-814, 2018 (SCI-Expanded)
The concept of a constrictor was used by several mathematicians to characterize the asymptotic behavior of operators. In this paper we show that a positive LR-sequence on a KB-space is mean ergodic if the LR-sequence has a weakly compact constrictor. Moreover if a weakly compact constrictor is an order interval, then a positive LR-sequence converges strongly onto the finite dimensional fixed space. As a consequence we investigate also stability of Markovian LR-sequences and the existence of lower bound functions on KB-spaces.