2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/27743While multifractal spectra are convex, general field theoretic arguments show that power of field operators $ϕ^f$ yield a concave spectrum of exponents as function of $f$. This is resolved by appropriate choice of operators to describe multifractal moments. In a Lagrangian field theory of two mutually interacting species of fields $ϕ,ψ$, operators $O_{f'f}=ψ^{f'}ϕ^f$ with traceless symmetry give rise to multifractal spectra of harmonic diffusion near absorbing fractals when evaluated for zero component fields.14 pages, revtex, 2 latex picturesCondensed Mattertext