On the existence of states on MTL-algebras

The aim of this paper is to investigate the existence of Bosbach states and Riečan states on MTL-algebras. We prove that an MTL-algebra L has Bosbach states if and only if L has an MV-filter. We also establish that L has a state-morphism if and only if L has a maximal MV-filter. Furthermore, we obtain the necessary and sufficient condition for an MTL-chain having Riečan states.