Does photon self energy contribute to the speed of light?

Click For Summary
SUMMARY

The discussion centers on the role of photon self-energy and its implications for the speed of light. It establishes that photons are massless due to the Ward identity, which prevents quantum effects from generating mass. The Higgs mechanism is noted as an exception, specifically in superconductors where Cooper pairs lead to massive photonic quasi-particles. The conversation concludes that disabling photon-matter interactions would render photons undetectable, making the concept of their speed irrelevant.

PREREQUISITES
  • Understanding of quantum electrodynamics (QED)
  • Familiarity with the Higgs mechanism and its implications
  • Knowledge of superconductivity and Cooper pairs
  • Basic principles of particle physics and gauge fields
NEXT STEPS
  • Research the implications of the Higgs mechanism in superconductors
  • Explore the concept of photon-matter interactions in quantum electrodynamics
  • Study the properties of massless gauge fields in particle physics
  • Investigate the role of self-energy in quantum field theory
USEFUL FOR

Physicists, quantum field theorists, and students of particle physics seeking to deepen their understanding of photon behavior and interactions in various mediums.

Heidi
Messages
420
Reaction score
40
TL;DR
Role of the self energy
Hi Pf

I read that in the light propagator there are loops of electrons. What would be the consequences if
we could switch them off (or neglect them)? would it modify the speed of the photons?
 
Physics news on Phys.org
Since photons are described by a massless gauge field there's a Ward identity ensuring that quantum effects cannot generate a mass for photons. So photons stay massless.

The only exception is the Higgs mechanism. In the context of the photons it occurs in superconductors, where due to the formation of Cooper pairs of electrons a Higgs mechanism occurs for the corresponding in-medium QED. I.e., the photonic quasi-particles within a superconductor are massive.
 
  • Like
Likes   Reactions: Heidi
Heidi said:
What would be the consequences if we could switch them off

That could only be done consistently by turning off the photon-matter interaction, so such photons could neither be generated nor detected. It does not make sense to talk about the speed of such things.
 
  • Like
Likes   Reactions: Heidi and vanhees71

Similar threads

Undergrad 2-Slit: How do we know photon guns only produce single photons?
  • · Replies 33 ·
2
Replies
33
Views
2K
Undergrad Is the mass of a photon stationary in space?
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Breaking the Light Speed Barrier?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Why is the speed of photons different?
  • · Replies 4 ·
Replies
4
Views
1K
High School Transferring information faster than the speed of light
  • · Replies 24 ·
Replies
24
Views
3K
Undergrad Speed of information in a medium
  • · Replies 38 ·
2
Replies
38
Views
5K
Undergrad Question about the Photoelectric Effect and the Work Function of a Metal
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad What does it really mean that photons are quanta of light?
  • · Replies 15 ·
Replies
15
Views
2K
High School Why do photon polarization experiments show similar outcomes in different situations?
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad Does a certainty in the position imply infinite variation in speed?
  • · Replies 4 ·
Replies
4
Views
1K