2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28312We consider the effect of classical phase fluctuations on the quasiparticle spectra of underdoped high-$T_c$ cuprate superconductors in the pseudogap regime above $T_c$. We show that photoemission and tunneling spectroscopy data are well accounted for by a simple model in which mean field d-wave quasiparticles are semiclasically coupled to supercurrents induced by fluctuating unbound vortex-antivortex pairs. We argue that the data imply that transverse phase fluctuations are important at temperatures above $T_c$, while longitudinal fluctuations are unimportant at all temperatures.8 pages REVTeX, 3 figures included. Final version to appear in Dec. 1 PRB; extensive discussion of the validity of the model and other clarifying remarks addedSuperconductivityStrongly Correlated Electronstext