Eliminating on the Divergences of the Photon Self - Energy Diagram in   (2+1) Dimensional Quantum Electrodynamics
  The divergence of the photon self - energy diagram in spinor quantum electrodynamics in $(2+1)$ dimensional space time- $(QED_3)$ is studied by the Pauli - Villars regularization and dimensional regularization. Results obtained by two different methods are coincided if the gauge invariant of theory is considered carefully step by step in these calculations. 
Nguyen Suan Han, Nguyen Nhu Xuan