2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/53318Necessary and sufficient conditions are found for any object in $3+1$ dimensions to have integer rather than fractional fermion number. Nontrivial examples include the Jackiw-Rebbi monopole and the already well studied Su-Schrieffer-Heeger soliton, both displaying integer multiples of elementary charges in combinations that normally are forbidden.12 pagesHigh Energy Physics - Theorytext