Lecture

Dark Matter: Evidence and Candidates

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Description

This lecture focuses on the topic of dark matter, beginning with a recap of previous discussions on baryogenesis and the thermal history of the universe. The instructor transitions to dark matter, emphasizing the evidence for its existence and the various candidates proposed to explain it. The lecture outlines the significant role dark matter plays in cosmology, noting that while its existence is well-supported by observational data, its exact nature remains unknown. The instructor discusses the historical observations that led to the recognition of dark matter, including rotation curves of stars in galaxies and gravitational lensing effects. The lecture also covers the theoretical implications of dark matter, including its properties such as being stable and weakly interacting. Various candidates for dark matter are explored, including neutrinos, axions, and WIMPs, along with their respective challenges and constraints. The discussion concludes with the potential for dark matter to consist of primordial black holes, highlighting the ongoing research and exploration in this field.

Official source

Ontological neighbourhood

Astronomy

Astrophysics: Physical cosmology

Physics

Particle physics: Standard Model

Related concepts (32)

Cosmology

Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff, in Cosmologia Generalis. Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation myths and eschatology. In the science of astronomy, cosmology is concerned with the study of the chronology of the universe.

Physical cosmology

Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood.

Non-standard cosmology

A non-standard cosmology is any physical cosmological model of the universe that was, or still is, proposed as an alternative to the then-current standard model of cosmology. The term non-standard is applied to any theory that does not conform to the scientific consensus. Because the term depends on the prevailing consensus, the meaning of the term changes over time. For example, hot dark matter would not have been considered non-standard in 1990, but would be in 2010.

Cosmological constant

In cosmology, the cosmological constant (usually denoted by the Greek capital letter lambda: Λ), alternatively called Einstein's cosmological constant, is the constant coefficient of a term that Albert Einstein temporarily added to his field equations of general relativity. He later removed it. Much later it was revived and reinterpreted as the energy density of space, or vacuum energy, that arises in quantum mechanics. It is closely associated with the concept of dark energy.

Universe

The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. According to this theory, space and time emerged together 13.787billion years ago, and the universe has been expanding ever since the Big Bang. While the spatial size of the entire universe is unknown, it is possible to measure the size of the observable universe, which is approximately 93 billion light-years in diameter at the present day.

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