Relativistic Time Dilation in an Expanding Universe: Implications for Cosmic Age, Dark Energy and the Hubble Tension

This paper explores the role of relativistic time dilation in an expanding universe and its impact on cosmic observations. It proposes that the apparent acceleration of the universe may be an effect of time dilation rather than a physical force like dark energy. This approach suggests a revised interpretation of cosmic age and the expansion tensions in cosmology. Additionally, the observer-dependent nature of cosmic time introduced in this framework may offer insights into gravity and its relationship with quantum mechanics, providing a possible avenue toward unifying general relativity with quantum gravity.