2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34490We develop the general formalism to study the low energy regime of the brane world. We apply our formalism to the single brane model where the AdS/CFT correspondence will take an important role. We also consider the two-brane system and show the system is described by the quasi-scalar tensor gravity. Our result provides a basis for predicting CMB fluctuations in the braneworld models.5 pages, talk presented at The 12th Workshop on General Relativity and Gravitation, Tokyo, Japan, November, 2002General Relativity and Quantum Cosmologytext