Oscillating Cosmological Model

This thesis presents an oscillating universe model where the cosmos expands and contracts cyclically, described by a sinusoidal scale factor that prevents total collapse or runaway expansion. It demonstrates alternating phases of accelerated and decelerated expansion, aligning with observations like the universe’s current acceleration, and estimates the universe’s age at approximately 13.6 billion years, close to the observed 13.8 billion years. The model avoids singularities by proposing smooth transitions between phases and predicts future contraction driven by cyclic dynamics. It adapts standard cosmological equations to this framework, addresses risks like spacetime tearing during extreme phases by constraining parameters, and explores energy conditions to ensure physical realism. Serving as an alternative to the ΛCDM model, the work provides detailed mathematical derivations and appendices on technical aspects like stress analysis, aiming to inspire further research into cyclical cosmology and observational comparisons.