The Definition of the Universe
The Universe is the entirety of all space and time. This includes space, time, and energy. The prevailing cosmological model of the universe is the Big Bang theory. It posits that the universe was created at the Big Bang. The prevailing cosmological theory is based on the observation that all matter is created at the Big Bang. However, this model is contested. There are many alternatives to this Big Bang theory.
One possible explanation is that dark energy is a cosmological constant. According to this theory, the Universe contains a variable amount of dark energy. This is the same theory that describes the big bang theory, in which dark energy is the driving force behind the expansion of the universe. It is possible to define the universe as a filamentary structure with multiple levels of complexity. This is also consistent with the observed structures in the universe. The large scale structure of the Universe can be categorized as either a spiral or a sphere.
The sphere-like structure of the universe is in agreement with the observed curvature of space. However, the density of matter in the Universe is different from that of our world. This difference in density makes it difficult to measure the deceleration parameter with an accurate instrument. In fact, many scientists are skeptical about the validity of this model. In the meantime, there are many other theories that claim that the deceleration parameter is a purely numerical measure of the expansion rate of the universe.