2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/136480We calculate the Ehrenfest-time dependence of the leading quantum correction to the spectral form factor of a ballistic chaotic cavity using periodic orbit theory. For the case of broken time-reversal symmetry, our result differs from that previously obtained using field-theoretic methods [Tian and Larkin, Phys. Rev. B 70, 035305 (2004)]. The discrepancy shows that short-time regularization procedures dramatically affect physics near the Ehrenfest-time.6 pages, 1 figureChaotic DynamicsMesoscale and Nanoscale Physicstext