A bounce cosmology that fits Planck data as well as inflation

Instead of an inflationary epoch, this model replaces the Big Bang singularity with a quantum bounce: the universe contracts, bounces, then expands, with a scalar field carrying an exponential potential mimicking dust before the bounce and dark energy afterward. MCMC fits to the full Planck 2018 dataset — including lensing — constrain the model's free parameters and yield a spectral index consistent with observations. Statistical comparison shows neither model is preferred by CMB data alone, meaning the bounce scenario remains a competitive alternative to inflation on current observational grounds.