Extremal chiral N = 4 SCFT with c = 24

Abstract

We construct an extremal chiral N = 4 superconformal field theory with central charge 24 from a ℤ2 orbifold of the chiral bosonic theory with target ℝ24/ Λ, where Λ is the Niemeier lattice with root system A212. This construction is analogous to constructions of extremal chiral N = 1 and N = 2 CFTs with c = 24, where Λ = ΛLeech and the Niemeier lattice with root system A124, respectively. The theory has a discrete symmetry group related to the sporadic group M11.