Editing Vertex operator algebra (section)

=== Vertex algebra associated to a surface defect === 
A vertex algebra can arise as a subsector of higher dimensional quantum field theory which localizes to a two real-dimensional submanifold of the space on which the higher dimensional theory is defined. A prototypical example is the construction of Beem, Leemos, Liendo, Peelaers, Rastelli, and van Rees which associates a vertex algebra to any 4d ''N''=2 [[Superconformal algebra|superconformal]] field theory. <ref name="Beemetal2015">{{cite journal |last1=Beem |last2=Leemos|last3=Liendo|last4=Peelaers|last5=Rastelli|last6=van Rees|title=Infinite chiral symmetry in four dimensions. |journal=Communications in Mathematical Physics |date=2015 |volume=336 |issue=3 |pages=1359–1433|doi=10.1007/s00220-014-2272-x |arxiv=1312.5344 |bibcode=2015CMaPh.336.1359B |s2cid=253752439 }}</ref> This vertex algebra has the property that its character coincides with the Schur index of the 4d superconformal theory. When the theory admits a weak coupling limit, the vertex algebra has an explicit description as a [[Vertex operator algebra#Additional constructions |BRST reduction]] of a bcβγ system.