Learning and Knowledge in Social Networks Robert Carrington Abstract: For most purposes, the information an agent can readily access is just as important as the agent’s knowledge. This thesis explores several approaches to reasoning about the information agents in a network can access. The first section introduces a modality for information from immediate connections, and axiomatizes the resulting epistemic logic (EAL). I also introduce and axiomatize iterated version of the logic (IAL), which considers information along multiple edges of access. I prove both of these logics complete for epistemic models equipped with an edge relation. I define and axiomatize two additional logics for access without completeness – a version with restricted access (RAL) and one extending the existing framework of epistemic friendship logic with iterated access modalities (IFL).