Ghosts Definition and 18 Threads

I understand how to regularize the integrals in a electron vertex function using Pauli–Villars regularization, however in books like Schwartz this is seen as having introduced some "ghosts fields". How do I get that idea? When writing in that vertex function...

Summary: In QFT, if we add a gauge breaking term to the Lagrangian, do we still need to introduce Faddeev-Popov ghost particles? Ghosts seems to be introduced to maintain gauge invariance. But suppose we have eliminated the gauge invariance, from the start, by explicitly introducing a gauge...

I am fascinated by quantum physics but, I can't do the math to save my life. I teach psychology for Grambling State University. I am putting together a research grant with the NSF for a Social Science experiment. The work I am doing now is in the paranormal - or better put, prediction of...

The website on the main page on the lower right will tell you the staff that is on, and some of the members, along with that it tells you how many guests and how many "ghosts" are these just random computers that have left Physics Forums open in another tab? (Something I have been guilty of many...

Hi all, Don't worry, I'm not one of those wackos trying to convince you ghosts exist. I don't even believe in spirits. What I do believe is that people are really experiencing real things, but I believe that there is a scientific explanation to it all. I'm not a physics wiz, so I'm hoping to...

So my text (Ryder 2nd edition, page 252) is defining the "pure gauge-field Lagrangian" as: G_{\mu \nu}\equiv \partial_{\mu}A_{\nu} - \partial_{\nu}A_{\mu}-ig\left[ A_{\mu},A_{\nu}\right] \mathcal{L} = -\frac{1}{4}Tr G_{\mu \nu} G^{\mu \nu} Dumb question: Isn't G_{\mu \nu} G^{\mu...

Please teach me this: Why can we not consider Faddeev ghost as a type of fermi fields,but consider them as a scalar under Lorentz transformation,therefore have wrong relation between spin and statistics? Thank you very much for your kind helping.

I have a question about Fadeev-Popov (FP) ghosts. FP ghosts brake the gauge symmetry of the lagrangian and solve the problem of the divergence of the physical amplitudes, due to the gauge equivalence of the states. My question is: is it a renormalization process? I mean, the renormalization...

Hey guys, I have a question about how to incorporate ghosts in practical calculations. So, from what I understand I have to add a factor of -1 for each closed gluon loop, right? But there are two ghost fields, c and \bar{c} appearing when I quantize the path integral. Does that mean that I also...

People all over the Earth have to come across the term "ghost" at some point of their life (probably). Generally it has become a culture that any ordinary layman would believe in ghosts and any scientist would say that "there is no such thing as ghost..and it is a stupid superstition.." Then...

A thread in the digital cameras forum made me think this might be a good debate topic without getting into the passions of religion and politics. I admit that there are strange and frequently un-explainable things, (so far), that happen but I do not believe in ghosts.

Hi everyone I'm new here--a first year penn state undergrad--and the extent of what i know is the popularizations of quantum physics, so i might be a little off base, and I know that what I'm about to ask is borderline unscientific, but here goes Everett wrote his theory of the many-worlds...

If ghosts could be seen then its obvious that they are emitting visible light,and light is nothing both electromagnetic fields. which would imply that they are made of physical matter,as everbody knows that electromagnetic fields couple to accelerating charges. What is even more...

what exactly are ghosts? i am guessing that they have something to do with overcounting feynman diagrams or something but i am still not sure. also is a so-called "longitudinal" free photon considered to be a ghost?

Wow 3 days ago I just left my computer to bring a cup of tea for myself, but when I came back :bugeye: :bugeye: :bugeye: lots of windows were opened and the place of files on the desktop were changed :rolleyes: :rolleyes: :rolleyes: Please tell me they were done by a ghost...

UK Man "Foils" Ghosts http://www.findarticles.com Current Science, Jan 19, 2001 Ghosts Busted in Haunted Rooms "Vic Tandy, a computer expert, was working late one night in a laboratory in Warwick, England, which had a history of being haunted. At one point, a cold sweat and a feeling of...

http://www.cnn.com/2003/TECH/science/09/08/ghosts.sounds.reut/index.html

Reported sightings of ghosts indicate that they move relatively normaly with respect to the observer. Since the Earth is moving at a velocity of approx 200 miles per second through space does this mean that they are being dragged just like us by the gravitational field of the earth?