Quantum Field Theory Concepts Zee ch 1 and 2

Front

Field

Back

An entity that assigns a value (number or vector) to every point in space and time.

Front

Quantum Amplitude

Back

A complex number that determines the probability amplitude for a process in quantum mechanics.

Front

Action (S)

Back

The integral of the Lagrangian over time; it governs the motion in classical and quantum systems.

Front

Path Integral

Back

The method of summing over all possible histories weighted by the action to compute quantum probabilities.

Front

Symmetry

Back

A transformation that leaves the physical laws unchanged.

Front

Gauge Symmetry

Back

A symmetry transformation that varies from point to point in space-time.

Front

Lagrangian

Back

A function describing the difference between kinetic and potential energy, governing system dynamics.

Front

Noether's Theorem

Back

A fundamental theorem in theoretical physics that relates symmetries and conservation laws.

Front

Propagator

Back

Describes the probability amplitude for a particle to travel from one space-time point to another.

Front

Feynman Diagram

Back

A pictorial representation of particle interactions used in perturbative quantum field theory.