2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67403We relate the semiclassical asymptotics of the 6j symbols for the representation theory of the quantized enveloping algebra U_q(sl_2) at q a primitive root of unity, or q positive real, to the geometry of non-Euclidean tetrahedra. The formulas are motivated by the geometry of conformal blocks in the Wess-Zumino-Witten model; they generalize formulas in the case q = 1 of Wigner, Ponzano and Regge, and Schulten and Gordon, proved by J. Roberts.34 pages. Rewritten. To appear in Selecta MathQuantum AlgebraSymplectic Geometry20G42 (53D50)text