Lecture

Fermion Production: Implications for Gauge Fields and Inflation

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Description

This lecture discusses the production of fermions in the context of gauge fields during inflation. It begins by examining the dynamics of fermion production in a helical gauge field background, highlighting the role of electric and magnetic fields. The instructor explains how fermions are accelerated in this background and how their production can inhibit further gauge field generation. The Dirac equation is introduced to analyze the quantized energy levels in constant magnetic fields and the time-dependent energy levels in electric fields. The lecture also covers the implications of fermion back-reaction on gauge field production, emphasizing the non-linear nature of the system and the challenges in finding stationary solutions. The discussion extends to the implications for late universe scenarios, including magnetogenesis and baryogenesis, and the potential for new avenues in understanding cosmic phenomena. The instructor concludes by addressing open questions and the need for further research in this area, particularly regarding the interplay between fermions and gauge fields in cosmological models.

Official source

Ontological neighbourhood

Physics

Particle physics: Standard Model

Astronomy

Astrophysics: Physical cosmology

Related concepts (32)

Inflation (cosmology)

In physical cosmology, cosmic inflation, 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 from seconds to between and seconds after the Big Bang. Following the inflationary period, the universe continued to expand, but at a slower rate. The acceleration of this expansion due to dark energy began after the universe was already over 7.7 billion years old (5.4 billion years ago).

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.

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.

Electromagnetic field

An electromagnetic field (also EM field or EMF) is a classical (i.e. non-quantum) field produced by moving electric charges. It is the field described by classical electrodynamics (a classical field theory) and is the classical counterpart to the quantized electromagnetic field tensor in quantum electrodynamics (a quantum field theory). The electromagnetic field propagates at the speed of light (in fact, this field can be identified as light) and interacts with charges and currents.

Baryogenesis

In physical cosmology, baryogenesis (also known as baryosynthesis) is the physical process that is hypothesized to have taken place during the early universe to produce baryonic asymmetry, i.e. the imbalance of matter (baryons) and antimatter (antibaryons) in the observed universe. One of the outstanding problems in modern physics is the predominance of matter over antimatter in the universe. The universe, as a whole, seems to have a nonzero positive baryon number density.

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