Ghosts Definition and 34 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...

This video gets into the phenomena in nature that can create the imagined appearance of ghostly events: And in the end there is no evidence for Ghosts.

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...

Definition 1: Ghosts are the "creatures" which might be made of particles as we are, but unseen (with the use of photons). Premise 1: We are made of particles or atoms which enable us to think and make us what we are (human creatures). Premise 2: Their might exist creatures which are made...

I was reading a rapid reader called The Canterville Ghost by Oscar Wilde. According to that US believed less in ghosts in comparison with UK. So a question arose in me that why not survey people here and discuss. I know Halloween is celebrated there in US. So they also do some scary things. My...

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 like to ask this question every now and then to new people. So what do you think, real or a bedtime story that has been taken too far? Me personally, I absolutely believe in ghosts. As a kid I had this crazy experience that lasted all night long and I can't even begin to explain. I've only...

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...

Personally, I don't really believe in demons etc. If you do, I don't have any problems. Science needs some parameters to work on anything. e.g. To work on air one should know its temperature, composition, etc. Sometime in the past a clever and smart magician could have used a colored gas like...

What I really want to know is are ghosts real? Do ghosts exist? I got really freaked out after my friend said his friend can see them (like dead people, especially in graveyards), and once his friend was standing next to a stranger and they could both see the same thing (a ghost obviously)... so...

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.

How could one go about proving that ghosts do not exist? Seems like we could make some basic assumptions about what ghosts are, and proceed to prove that that particular 'brand' of ghost cannot exist. Any ideas?

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?

I woke up at about 3am the other night and went to the kitchen to get a drink. As I walked back into my room I saw someone standing next to my bed. They walked into the bathroom and disappeared. I only saw it out of the corner of my eye and I was half asleep, but it scared me anyway.

Oh my, approximately the same percent of people in the US that say they are baseball fans also believe in ghosts, UFO's, that the U.S. made the right decision to invade Iraq, and approve of the job President Bush is doing. What does this mean? Ok, just showing that how you represent data...

Ok, so I have this friend who believes in ghosts. I, on the other hand, neither believe nor disbelieve in ghosts or spirits; all I said was that there has not yet been any scientific evidence proving their existence, so I'm neutral. So he says that (I think he said back in the 70's) there...

[sorry if this has been asked before, but this is a question I've been asking people] Ok, now just about every one at one point has heard about a "ghost". And lately I have been thinking to myself that I have been seeing them around the house, because when i come out of a room, and i pass...

This is part of a survey I am doing for a class project, wanted to get a sampling from the scientific community. Many Thanks.

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...

Obviously we don't know anything about the credibility of these videos and pictures. This is just for your entertainment folks. Requires flash: http://www.ebaumsworld.com/ghosts.html

What do you guys think about ghosts? The idea that ghosts exist is usually thought to be a by-product of some sort of supernatural event, such as the death of someone generating a disembodied spirit or soul. Something that is beyond death, but trapped between here (Earth) and there (Heaven or...

Rather than create a new thread for each news report on ghosts, I will post the newest links here on a semi-regular basis. Please feel free to add any interesting stories. Much ado about ghost stories in Shakespeare: http://www.abqtrib.com/archives/news03/101803_news_tales.shtml

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

I have read recently i can't find the site now but, some one suggested that when ghosts apear that you are seeing into the past. It went on to exsplain many occurances when these things happen like why the tempture drops is because energry is taken from an area surrounding the "ghost" and the...

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?