2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/145791We calculate, as a function of temperature and density, the electron-electron interaction induced quasiparticle effective mass renormalization in 2D electron systems within the leading-order dynamically screened Coulomb interaction expansion. We find an unexpected nonanalyticity and nonmonotonicity in the temperature dependent effective mass with the renormalized mass linearly increasing with temperature at low temperatures for all densities.This is a revised and extended version. Accepted for publishing by PRBMesoscale and Nanoscale PhysicsStrongly Correlated Electronstext