**Are you an EPFL student looking for a semester project?**

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Lecture# Understanding Vacuum Energy in Inflation

Description

This lecture delves into the concept of vacuum energy during inflation, focusing on the time evolution of a scalar field and its impact on time translation invariance. The discussion covers the dynamics of scalar and vector fields, the constraints on the Abelian field, and the implications of non-trivial vacuum energy. The instructor also addresses feedback on problem sessions and homework, emphasizing the importance of reaching out for clarification. Additionally, details about the upcoming course exam and oral exam slots are provided, along with insights into the structure of the exams and the opportunity for students to connect with the instructors.

Login to watch the video

Official source

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related concepts (282)

Related lectures (1,000)

Quantum chromodynamics

In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a type of quantum field theory called a non-abelian gauge theory, with symmetry group SU(3). The QCD analog of electric charge is a property called color. Gluons are the force carriers of the theory, just as photons are for the electromagnetic force in quantum electrodynamics.

Lattice QCD

Lattice QCD is a well-established non-perturbative approach to solving the quantum chromodynamics (QCD) theory of quarks and gluons. It is a lattice gauge theory formulated on a grid or lattice of points in space and time. When the size of the lattice is taken infinitely large and its sites infinitesimally close to each other, the continuum QCD is recovered. Analytic or perturbative solutions in low-energy QCD are hard or impossible to obtain due to the highly nonlinear nature of the strong force and the large coupling constant at low energies.

QCD matter

Quark matter or QCD matter (quantum chromodynamic) refers to any of a number of hypothetical phases of matter whose degrees of freedom include quarks and gluons, of which the prominent example is quark-gluon plasma. Several series of conferences in 2019, 2020, and 2021 were devoted to this topic. Quarks are liberated into quark matter at extremely high temperatures and/or densities, and some of them are still only theoretical as they require conditions so extreme that they cannot be produced in any laboratory, especially not at equilibrium conditions.

Chirality (physics)

A chiral phenomenon is one that is not identical to its (see the article on mathematical chirality). The spin of a particle may be used to define a handedness, or helicity, for that particle, which, in the case of a massless particle, is the same as chirality. A symmetry transformation between the two is called parity transformation. Invariance under parity transformation by a Dirac fermion is called chiral symmetry. Helicity (particle physics) The helicity of a particle is positive (“right-handed”) if the direction of its spin is the same as the direction of its motion.

Gluon field

In theoretical particle physics, the gluon field is a four-vector field characterizing the propagation of gluons in the strong interaction between quarks. It plays the same role in quantum chromodynamics as the electromagnetic four-potential in quantum electrodynamics - the gluon field constructs the gluon field strength tensor. Throughout this article, Latin indices take values 1, 2, ..., 8 for the eight gluon color charges, while Greek indices take values 0 for timelike components and 1, 2, 3 for spacelike components of four-dimensional vectors and tensors in spacetime.

Quantum Chromodynamics Overview

Covers Quantum Chromodynamics, including running coupling constant and confinement of quarks and gluons.

Quarks and Leptons: Spin-1/2 and Dirac Notation

Introduces quarks and leptons, discussing their spin, charge, and notation.

Fermion Masses and Mixings

Explores fermion masses, chiral nature, and Yukawa couplings.

Partons and Hadrons: Strong Force and Deep Inelastic Scattering

Explores partons, hadrons, strong force, deep inelastic scattering, elastic and inelastic scattering, and Bjorken scaling.

Standard Model Overview

Provides an in-depth analysis of the Standard Model, covering topics such as the Higgs mechanism, gauge boson interactions, and the role of chirality in particle physics.