Recent content by Tomishiyo

This explains a lot. Then the answer to my other questions, I suppose, must be that the Green function to the Dirac operator is a matrix and for some convenient reason Tong factored out the ##i##. Thank you for your answer.

Thank you for your answer. The propagators I'm referring are for the free scalar field and the free spinor field. I'm not sure if this answers your question because I understand so little about propagators that I'm not even used to the terminology. As for the second part of your answer, I'll...

I'm studying QFT by David Tong's lecture notes. When he discusses causility with real scalar fields, he defines the propagator as (p.38) $$D(x-y)=\left\langle0\right| \phi(x)\phi(y)\left|0\right\rangle=\int\frac{d^3p}{(2\pi)^3}\frac{1}{2E_{\vec{p}}}e^{-ip\cdot(x-y)},$$ then he shows that the...

Thank you all by the responses, specially thanks to @mfb for the mentions and @nrqed for the reading recommendations. I've seen the term in the context of hadronic high energy interaction models, specifficaly, I was reading about the Sybill model. The paper in question is authored by Sergey...

Sadly no, this is all information I could get. Thanks by the courtesy, even it being automated.

I'm doing some reading about high energy hadronic interaction models, and now and there some papers mention the term "eikonalization". Yet, I could not find any definition about it anywhere, except a vague one that states it is a kind of unitarization of an operator (yet I cannot understand how...

Thank you all for your answers, and apologies for my delayed answer. I was not thinking only about atoms, but it would be interesting to know how the experiment is done in this case. Also, does anyone knows any paper describing one of such experiments?

Standard quantum mechanics text-books discusses Born rule, which states that the probability of finding a particle in a certain region in space is given by $$ |\Psi ({\bf r},t)|^2d^3r $$ Thing is, I never have seen a discussion about how you can actually measure the particle position in a...

What do you mean by "use the mass definition"? Up to point 6, what I got was: \frac{1}{m}\frac{dP^0}{d\tau}=-\frac{1}{m^2 c^2}\frac{\partial \phi}{\partial t}(P^0)^2 The equation agrees with HEL, his expression on p.154 reads: \frac{d^2x^{\mu}}{d\tau^2}+\Gamma^{\mu}_{\ \...

Reading HEL I realized why you ask me for a formal definition for energy conservation. It is indeed not well defined in GR context, forgot about that. I'll try to read textbook again and search for some clue about that. All I could do for the moment was to show that, in a non-relativistic case...

Yeah, it is Modern Cosmology. I got it confused with Ryden's "Introduction to Cosmology". Also, I'm sorry for forgetting to mention that page number and exercise, those are 54 and 3, respectively. I see. Thanks by the explanation. But the parameter ##\lambda## isn't supposed to be...

Thank you for your answer, strangerep, and I'm sorry for not answering it right away. The question comes from Dodelson's "Introduction to Modern Cosmology". This is the only textbook I'm using at the moment. Positive. Christoffer symbol are given by: \Gamma^{\mu}_{\ \...

Anyone? Please :(?

Homework Statement The metric for a given particle traveling in the presence of a gravitational field is g_{\mu\nu}=\eta_{\mu\nu}+h_{\mu\nu}, where \eta_{\mu\nu} is the Minkowski metric, h_{00}=-2\phi (\phi the Newtonian gravitational potential); h_{i0}=0; and h_{ij}=-2\phi\delta_{ij}. Units...

Ok, thank you very much. I think I've done it :)