The Big Drop: A Cascade-Based Framework for Early Universe Dimensional Reduction

We propose a cosmological model, the Big Drop, in which the universe transitions from a high-dimensional, high-energy metastable state to a 3+1-dimensional low-energy vacuum through a discrete cascade of dimensional and vacuum-energy reductions. These transitions are mediated by a scalar field with a multi-well potential and governed by energy- and entropy-conserving dynamics. We derive an effective 4D action, calculate the scalar and tensor primordial power spectra, and show how the model addresses standard cosmological puzzles such as the horizon and flatness problems. The cascade induces unique observational signatures, including oscillatory features in the cosmic microwave background (CMB) power spectrum and a background of gravitational waves. We compare the Big Drop's predictions with those of inflation and demonstrate its potential as a viable alternative early-universe scenario consistent with current data. Critically, the Big Drop provides a natural bridge between quantum gravity frameworks and observable cosmology.