The SU(1|2) and SU(2|2) Sectors from Superstrings in AdS5 x S5
  For the \kappa-symmetry gauge fixed superstring action in AdS_5 x S^5 we consider the fermionic fluctuations over a circular bosonic string background with two angular momenta and two winding numbers in S^5. The SU(2)-type redefinitions of fermionic fields and the first-string limit generate a truncated fermionic action for the SU(1|2) sector. It is expressed in a two-dimensional Lorentz-invariant form of a massive Dirac fermion and the plane-wave spectrum for the fermionic excitations is derived. The fermionic spectrum for the SU(2|2) sector is also analyzed. 
Shijong Ryang