Jump to content

Talk:Fermionic field

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia
(Redirected from Talk:Dirac field)

Untitled

[edit]

I removed the text

"Since all observables are built out of an even number of fermion fields, the commutation relation vanishes between any two observables at spacetime points within the light cone. As we know from elementary quantum mechanics two simultaneously commuting observables cannot be measured simultaneously. We have therefore correctly implemented Lorentz invariance for the Fermion field, thereby preserving causality."

It's bad logic and mostly wrong. Melchoir 03:04, 30 October 2005 (UTC)[reply]

This article is mostly about the free Dirac field, but fermion fields are far more general than that! QFT 19:46, 29 January 2006 (UTC)[reply]

The original text makes sense with some slight modifications. It should read

":Since all reasonable observables (such as energy, charge, particle number, etc.) are built out of an even number of fermion fields, the commutation relation vanishes between any two observables at spacetime points within the light cone. As we know from elementary quantum mechanics two simultaneously commuting observables cannot be measured simultaneously. We have therefore correctly implemented Lorentz invariance for the Fermion field, and preserved causality."

See for example Peskin and Schroeder pg. 56. DiracAttack 08:04, 15 September 2006 (UTC)[reply]


What is this entry about?

[edit]

This article doesn't really explain what a ferminonic field is. What is the physical reality of this field? It isn't the same as the supposed luminiferous ether (the classicaly imagined medium that light waves were once imagined to propagate through) yet the fermionic field seems to have an analogous role. Could someone flesh this out, without going into detailed mathematics? See also Bosonic field. RK 19:51, 21 May 2006 (UTC)[reply]

(David Edwards) As Whitaker pointed out in volume II of his history of the aether, quantum field theory allows a reentry of a relativistic ether; namely, spacetime is the seat of potential observables, i.e. it is a tectured medium.

See my (David Edwards) entry under limitations of quantum logic:

In any case, these quantum logic formalisms must be generalized in order to deal with supergeometry (which is needed to handle Fermi-fields) and non-commutative geometry (which is needed in string theory and quantum gravity theory). Both of these theories use a partial algebra with an "integral" or "trace". The elements of the partial algebra are not observables; instead the "trace" yields "greens functions" which generate scattering amplitudes. One thus obtains a local S-matrix theory (see D. Edwards). Since around 1978 the Flato school ( see F. Bayen ) has been developing an alternative to the quantum logics approach called deformation quantization (see Weyl quantization ).

The energy Ep in the second equation needs to be defined. Xxanthippe (talk) 23:16, 22 December 2009 (UTC).[reply]

Zero Rest Mass

[edit]

Should the section on zero rest mass from the Spinor field article be moved here? 70.247.169.197 (talk) 17:42, 21 August 2010 (UTC)[reply]

I came across Polar form of the Dirac equation on new page patrol, and it looked to me like that article is just a proof related to Dirac fields, which themselves are currently only covered as a section in this article about Fermionic fields in general, and thus it seems appropriate to merge its content here. I don't really understand any of the math though, so I'll leave it to other editors to figure out how to actually go about doing that. signed, Rosguill talk 05:21, 15 December 2018 (UTC)[reply]

Merging Polar Dirac Equation and this page

[edit]

As someone with a bit more background, I agree the aforementioned page should be a subsection of this pages Dirac field section Cmcraes (talk) 20:03, 28 March 2019 (UTC)[reply]