Register to reply

Coupling fermions to a scalar field: Interpretation problem

by blue2script
Tags: coupling, fermions, field, interpretation, scalar
Share this thread:
Feb20-08, 08:39 AM
P: 49
Hi all,

I have a little problem concerning the coupling of a fermion to CP^N (or better a 2D scalar O(3) model). Its not a mathematical type of problem. I just read on

"The coupling of fermions to the three-dimensional noncommutative $CP^{N-1}$ model: minimal and supersymmetric extensions"

The Lagrangian of this theory is written down in (2.1) and I am a bit lost as of interpreting this formula. There are three indegredients: 1. a scalar field, 2. a fermionic field and 3. a gauge field. Now, a scalar field represents a spin-0 field, right? The fermionic field is of spin 1/2. But now what is the gauge field? The scalar field may have some internal symmetry like O(3) but this won't affect the Lagrangian. I just don't understand what the gauge field is in this case.

Could somebody explain that to me? A big thanks in advance!!


PS: Also, of what physical interest is the scalar model besides being a nice toy model to study field effects? What could be the interpretation of a scalar field?
Phys.Org News Partner Physics news on
Detecting neutrinos, physicists look into the heart of the Sun
Measurement at Big Bang conditions confirms lithium problem
Researchers study gallium to design adjustable electronic components
Feb20-08, 06:15 PM
P: 932
For example, in a chiral supermultiplet, you can have a scalar field and Weyl fermion fields in the same supermultiplet.

Such scalar fields are candidates for the inflaton field that led to inflation (the Higgs doesn't quite work as that field).

Register to reply

Related Discussions
Energy-momentum tensor for a scalar field (sign problem!) Special & General Relativity 2
Magnetic field coupling Classical Physics 1
Scalar field and spin 1/2 field Quantum Physics 7
Scalar field Calculus & Beyond Homework 4
Finding an electric field from a scalar field Introductory Physics Homework 3