2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/173678We propose the notion of q-characters for finite-dimensional representations of quantum affine algebras. It is motivated by our theory of deformed W-algebras. We show that the q-characters give rise to a homomorphism from the Grothendieck ring of representations of a quantum affine algebra to a polynomial ring. We conjecture that the image of this homomorphism is equal to the intersection of certain "screening operators". We also discuss the connection between q-characters and Bethe Ansatz.47 pages, Latex2eQuantum AlgebraHigh Energy Physics - TheoryExactly Solvable and Integrable Systemstext