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...

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...

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

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

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

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...

inflation, is a theory of exponential expansion of space in the very early universe. Following the inflationary period, the universe continued to expand...

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...

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...

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...

proposed 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...

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

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...

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)...

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...

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

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...

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

measure the expansion of the universe Mark M. Phillips (1951–) used supernova observations to discover acceleration in the expansion of the universe, calibrated...

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...

Given the cosmological principle, Hubble's law suggested that the universe was expanding. Two primary explanations were proposed for the expansion. One...

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...

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...

1;: 5  the number density of photons in the CMB is one billion times (109) the number density of matter in the universe. Without the expansion of the universe...