• Aucun résultat trouvé

Derive equations of motion for the scalr field with the action S= Z d4x −1 2φ ∂µ∂µφ−m2 2 φ2 •Exercise 7.2

N/A
N/A
Protected

Academic year: 2022

Partager "Derive equations of motion for the scalr field with the action S= Z d4x −1 2φ ∂µ∂µφ−m2 2 φ2 •Exercise 7.2"

Copied!
1
0
0

Texte intégral

(1)

Quantum field theory Exercises 7.

2005-12-12

•Exercise 7.1.

Derive equations of motion for the scalr field with the action

S= Z

d4x

−1

2φ ∂µµφ−m2 2 φ2

•Exercise 7.2.

Consider the model of a massles scalar field S=

Z d4x1

2∂µφ ∂µφ and thedilatationtransformations

xµ →x0µ =eαxµ,

φ(x)→φ0(x0) =φ(x)e−dφα .

1. Show that this transformation is really a symmetry of the action for an appropriate choice ofdφ. Find the corresponfing Noether current and verify explicitly that it is conserved on the equations of motion.

2. Show that the mass term spoils the symmetry.

3. Show that the potential term of the formV(φ) =λ φ4does not spoil the dilatation sym- metry.

7

Références

Documents relatifs

[j -invariant] Let k be an algebraically closed field of characteristic different from 2

[r]

STEFFW.lqSEN, Les orbites p~riodiques dans le probl&me de

Hill employed rectangular coordinates with the time as independent variable... The agreement between these figures is as good as can be

From this we conclude that for all black hole solutions of our EDYM system, the Dirac spinors must vanish identically outside of the event hori- zon.. 4 Proof that ω

Write down the transition matrix between the bases

This homework is not compulsory, however, you may submit solutions to it, and if your mark is higher than one of the marks for assignment 1–4, the mark for this assignment will

In Special Relativity one defines the energy-momentum vector pi, for example, as an integral of over a space-like hypersurface where ni is the normal to a. From