2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/226156The 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.6 pages, 1 figureHigh Energy Physics - Theorytext