Lecture

Understanding 2D Adjoint QCD

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture by the instructor Maria Nuschel from the University of Minnesota delves into the beta functions of 2D adjoint QCD, a tractable toy model for studying more complex theories like 4D QCD. The talk covers the sharp definition of confinement, large N limit, symmetries, and anomalies in the theory. The discussion includes the significance of one-form symmetries, operator product expansion coefficients, and the implications of adding four Fermi terms to the action. The lecture also explores the effects of these terms on the theory's behavior, particularly in relation to confinement, and highlights the considerations when transitioning from the continuum to lattice calculations.

Official source

Ontological neighbourhood

Physics

Quantum field theory: Topics in quantum field theory

Related concepts (32)

Symmetry

Symmetry () in everyday language refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is invariant under some transformations, such as translation, reflection, rotation, or scaling. Although these two meanings of the word can sometimes be told apart, they are intricately related, and hence are discussed together in this article.

Anomaly (physics)

In quantum physics an anomaly or quantum anomaly is the failure of a symmetry of a theory's classical action to be a symmetry of any regularization of the full quantum theory. In classical physics, a classical anomaly is the failure of a symmetry to be restored in the limit in which the symmetry-breaking parameter goes to zero. Perhaps the first known anomaly was the dissipative anomaly in turbulence: time-reversibility remains broken (and energy dissipation rate finite) at the limit of vanishing viscosity.

Gauge theory

In physics, a gauge theory is a field theory in which the Lagrangian is invariant under local transformations according to certain smooth families of operations (Lie groups). The term gauge refers to any specific mathematical formalism to regulate redundant degrees of freedom in the Lagrangian of a physical system. The transformations between possible gauges, called gauge transformations, form a Lie group—referred to as the symmetry group or the gauge group of the theory. Associated with any Lie group is the Lie algebra of group generators.

Symmetry (physics)

In physics, a symmetry of a physical system is a physical or mathematical feature of the system (observed or intrinsic) that is preserved or remains unchanged under some transformation. A family of particular transformations may be continuous (such as rotation of a circle) or discrete (e.g., reflection of a bilaterally symmetric figure, or rotation of a regular polygon). Continuous and discrete transformations give rise to corresponding types of symmetries.

Gauge anomaly

In theoretical physics, a gauge anomaly is an example of an anomaly: it is a feature of quantum mechanics—usually a one-loop diagram—that invalidates the gauge symmetry of a quantum field theory; i.e. of a gauge theory. All gauge anomalies must cancel out. Anomalies in gauge symmetries lead to an inconsistency, since a gauge symmetry is required in order to cancel degrees of freedom with a negative norm which are unphysical (such as a photon polarized in the time direction). Indeed, cancellation occurs in the Standard Model.

Related lectures (54)

Brown-York Stress Tensor

Covers the Brown-York stress tensor and its relation to AdS/CFT correspondence.

Symmetry & Group Theory

Covers the fundamental concepts of symmetry and group theory.

Rotational Dynamics: Angular Momentum

Explains angular momentum for rotating solids and discusses symmetry in mass distribution.

Staggered Bosons: Symmetry and Gaplessness

Explores staggered bosons, lattice realizations of gapless field theories with symmetry protection, commutation relations, and criticality.

Limits and Operations on Limits