Topic-relevance and Hyperintensional Belief
Tianyi Chu

Abstract:
This thesis introduces a novel doxastic logic, denoted as L_TB , which addresses the challenges posed by traditional accounts of hyperintensionality. In L_TB , we use the notion of topic-relevance to achieve hyperintensionality, modeling belief based on the fragments generated by topics and information pieces.
In this thesis, we show that L_TB can deal with different variations of the logical omniscience problem and provide a nuanced interpretation of a model alethic operator within a doxastic context. We present a sound axiomatisation for L_TB and we compare L_TB with other existing hyperintensional theories.