Timeline for Why gauge invariance for electromagnetic fields?
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 17, 2014 at 14:56 | vote | accept | linuxfreebird | ||
| Mar 17, 2014 at 14:53 | comment | added | JamalS | It should be noted many symmetries are actually spontaneously (not explicitly) broken in Nature, for example $SU(2) \times U(1)_{L} \to U(1)_{EM}$. | |
| Mar 17, 2014 at 14:52 | comment | added | JamalS | No, certainly not. We introduce the Higgs field to avoid introducing mass terms which break symmetries, in a nutshell | |
| Mar 17, 2014 at 14:49 | comment | added | linuxfreebird | Whoa, the higgs field breaks charge conservation? | |
| Mar 17, 2014 at 14:48 | comment | added | JamalS | If you want to break gauge invariance, you need to add a term to the Lagrangian, e.g. a mass term. The reason we need the Higgs mechanism in the standard model for certain fields is because we can't add a mass term that preserves symmetries for those fields. | |
| Mar 17, 2014 at 14:44 | comment | added | linuxfreebird | Good answer. Where does the broken gauge invariance come into the math? Do we have to start with the Lagrangian? | |
| Mar 17, 2014 at 14:35 | history | answered | JamalS | CC BY-SA 3.0 |