Ghosh, Mainak2024-03-212024-03-212023-0477p.http://hdl.handle.net/10263/7440This thesis is under the supervision of Dr. Shamindra Kumar GhoshIn the classification programme of subfactors, the standard invariant plays a quintessential role. In this thesis, we furnish a 2-categorical perspective of the standard invariant of finite-index subfactors and further study algebraic structures (Q-systems) associated with themenQ-SystemsUnitary connectionsSubfactorsC*-2-categoriesThesis