Large-scale structure of the Universe
The composition and contents of the universe have changed over time,have influenced the Cosmos' evolution and will decide the Ultimate fate of the universe. After the Big Bang and for the next 3 billion years, the universe was Radiation dominated as can be evidenced from the Cosmic Microwave Background(CMB).For the next 3—7.7 billion years, the universe was matter dominated and its expansion started to progressively slow down, however, since then, the universe became dominated by a poorly understood form on vacuum energy known as Dark Energy. — a form of energy that has since then accelerated the universe's expansion.