Eliminating on the divergences o f the photon self - energy diagram in (2+1) dimensional quantum electrodynamics

The divergence o f the photon self-energy diagram in spinor quantum electrodynamicsin (2 + 1 ) dimensional space time- (QEDs) is studied by the Pauli-Villars regularization anddimensional regularization. Results obtained by two diiTerent methods are coincided i f the gaugeinvariant o f theory is considered carefully step by step in these calculations.