The expansion of the universe is the increase in distance between gravitationally unbound parts of the observable universe with time. It is an intrinsic...

Observations show that the expansion of the universe is accelerating, such that the velocity at which a distant galaxy recedes from the observer is continuously...

uniformity of the universe, known as the flatness problem, is explained through cosmic inflation: a sudden and very rapid expansion of space during the earliest...

and the accelerated expansion of the universe due to cosmic inflation. Tiny ripples in the universe at this stage are believed to be the basis of large-scale...

depends on knowing the rate of expansion, average density of matter, and the physical properties of the mass–energy in the universe. There is a strong...

the acceleration of the expansion of the universe, and about 25.8%±1.1% is dark matter. Ordinary ('baryonic') matter is therefore only 4.84%±0.1% of the...

beginning of the cosmological expansion. Initially, it was estimated that there may be 2 trillion galaxies in the observable universe. That number was reduced...

radiation give the cooling time of the universe since the Big Bang, and measurements of the expansion rate of the universe can be used to calculate its approximate...

The expansion of the universe is parametrized by a dimensionless scale factor a {\displaystyle a} . Also known as the cosmic scale factor or sometimes...

observations suggest that the expansion of the universe will continue forever. The prevailing theory is that the universe will cool as it expands, eventually...

the galaxies due to the expansion of the universe according to Hubble's law. A summarized timeline of important events in the field of cosmic voids from...

the first observational basis for the expansion of the universe, and today it serves as one of the pieces of evidence most often cited in support of the...

of several cosmological models in which the universe follows infinite, or indefinite, self-sustaining cycles. For example, the oscillating universe theory...

cosmological inflation, or just inflation, is a theory of exponential expansion of space in the early universe. The inflationary epoch is believed to have lasted...

unknown form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe. Assuming...

and the accelerated expansion of the universe can be characterized by the equation of state of dark energy. In the simplest case, the equation of state...

The heat death of the universe (also known as the Big Chill or Big Freeze) is a hypothesis on the ultimate fate of the universe, which suggests the universe...

constant to zero. That changed with the discovery in 1998 that the expansion of the universe is accelerating, implying that the cosmological constant may have...

contributions to the expansion of the universe as time elapses. Specifically, when the universe is radiation dominated, the expansion factor scales as...

The Big Crunch is a hypothetical scenario for the ultimate fate of the universe, in which the expansion of the universe eventually reverses and the universe...

cosmology, the shape of the universe refers to both its local and global geometry. Local geometry is defined primarily by its curvature, while the global...

explored the nature of matter and the cosmos in his 1225 treatise De Luce (On Light). He described the birth of the universe in an explosion and the crystallization...

Expansion of the universe, the increase of the distance between two distant parts of the universe with time Expansion (economics), an increase in the...

The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang (13.799 ± 0.021 billion years ago)...

Cosmological expansion was originally seen through observations by Edwin Hubble. Theoretical calculations also showed that the static universe, as modeled...

cosmological constant is zero. If so (absent some other form of dark energy), the expansion of the universe would be decelerating. However, after Saul Perlmutter...

Comoving distance factors out the expansion of the universe, giving a distance that does not change in time due to the expansion of space (though this may change...

apart by the expansion of the universe at a certain time in the future, until distances between particles will infinitely increase. According to the standard...

description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution...

The multiverse is the hypothetical set of all universes. Together, these universes are presumed to comprise everything that exists: the entirety of space...