Discover published sets by community

Dark energy is the name given to the unknown force that is causing the universe's expansion to accelerate over time. It comprises about 68% of the universe's total energy and plays a vital role in the current cosmological model.

CMB is the thermal radiation left over from the time of recombination in Big Bang cosmology. It provides a snapshot of the universe when it was only 380,000 years old and is a crucial piece of evidence for the Big Bang theory.

The ΛCDM model is the standard cosmological model that describes the universe as consisting of dark energy (Λ), cold dark matter (CDM), and ordinary matter. It explains the Big Bang, cosmic inflation, cosmic microwave background, and the large-scale structure. Its significance is as the most widely accepted model in cosmology.

Cosmic inflation is a theory that proposes a period of extremely rapid and exponential expansion of the universe shortly after the Big Bang. It is significant for explaining the uniformity of the CMB, the large-scale structure of the universe, and the absence of magnetic monopoles.

Dark matter is a form of matter thought to account for approximately 85% of the matter in the universe. Its presence is inferred from gravitational effects on visible matter and background radiation. In cosmology, it is significant for its role in the formation and evolution of galaxies and large-scale structures.

Galaxy filaments are the largest known structures in the universe, consisting of wall-like formations of galaxies interconnected by galaxy clusters. They are significant as they reflect the anisotropies in the early universe that were scaled up by cosmic inflation and shaped by dark matter.

Redshift is a phenomenon where the wavelength of light from an object is stretched, making the light appear redder. This occurs due to the expansion of the universe, and it is significant in cosmology because it provides information about the velocity and distance of celestial objects.

The cosmological constant is a term added by Einstein to his field equations of General Relativity to allow for a static universe. It is represented by Λ and is now understood to be associated with dark energy and the accelerated expansion of the universe.

The observable universe is the region of space that is theoretically possible for us to observe from Earth, bounded by the cosmic horizon. It holds significant importance in cosmology as it represents the limit of our observational data and encompasses all empirical evidence for cosmological theories.

The cosmic horizon is the maximum distance from which light could have traveled to an observer in the universe since the Big Bang. It is significant because it defines the observable universe and relates to the universe's age and expansion rate.

The Friedmann equations are a set of equations derived from General Relativity that describe the expansion of the universe. They form the framework of Big Bang cosmology and are significant for predicting the evolution of the universe based on its density and energy content.

Hubble's Law is the observation that the farther away a galaxy is, the faster it is moving away from us. It is represented by the equation

Structure formation refers to the formation of galaxies, galaxy clusters, and larger-scale structures from small early density fluctuations. This process is fundamental in cosmology for explaining how the current distribution of matter in the universe came to be.

The Big Bang theory describes the origin of the universe as a singular event about 13.8 billion years ago when all matter, energy, space and time expanded from a single point. Its significance in cosmology is as the prevailing explanation for the creation of the universe and the prediction of cosmic microwave background radiation.

The critical density is the value at which the density of the universe would create a flat geometry. It is significant in cosmology because it helps determine the overall shape of the universe and can indicate whether the universe will expand forever or eventually collapse.

Recombination refers to the era in the early universe when electrons combined with protons to form neutral hydrogen, allowing photons to travel freely. This event is significant for cosmology because it marks the release of the CMB and the transition from an opaque to a transparent universe.

The cosmological principle is the assumption that on large scales, the universe is homogeneous and isotropic. It is significant because it simplifies the mathematical modeling of the universe and is supported by observations of the CMB.

Baryogenesis is the theoretical physical process that produced an asymmetry between baryons and antibaryons in the early universe. This concept is significant because it attempts to explain why there is much more matter than antimatter in the universe.

Olbers' Paradox is the question of why the night sky is dark if the universe is infinite and eternally static, with an infinite number of stars. It is significant in cosmology as its resolution implies that the universe is dynamic and finite in age, contributing to the evidence for the Big Bang.