Dark Energy Dynamics, Spatial Curvature, Neither, or Both?

This colloquium talk by Bharat Ratra from Kansas State University explores the complex dynamics of dark energy and spatial curvature in cosmology. Delve into the evidence gathered over the past 25 years that has led cosmologists to conclude that dark energy constitutes the majority of the universe's energy budget, despite being only indirectly detected. Examine various dark energy models, including the standard ΛCDM cosmological model, and learn how their predictions compare with observational data to establish parameter constraints and evaluate data set consistency. Discover the latest observational constraints on dark energy dynamics, spatial curvature, and the Hubble constant, extending beyond the time-independent cosmological constant dark energy and flat spatial hypersurfaces of the standard model. The presentation concludes with key unresolved questions in contemporary cosmology, providing insight into future research directions in this field.