Recent content by PeterDonis

If by this you mean that there will be a difference in time dilation factor between two worldlines in any frame, that is not correct. Given two inertial worldlines in flat spacetime, their time dilation factors will be the same in the inertial frame called the Loedel frame, in which each...

No, not "time dilation in general"--only "time dilation" by Rindler's definition. Which, as has already been said, is what we in this thread have called "differential aging"--i.e., an invariant. He is not saying that "time dilation" by the other definition (the frame-dependent one) is "no...

Have you even read the reference you gave? Do you understand what it is describing in the text around the equation you referenced? I ask because I am extremely confused as to why you would even be asking the question quoted above if you had read the book. The book is telling you that the...

Due to the lack of any valid references as a basis for discussion, this thread is closed.

No references that you have given deal with this at all. If you cannot find any references, then we have no valid basis for discussion.

Asking if something is "impossible" is a useless question in an area of physics in which there is still much research being done. Given our best current upper bounds for Standard Model neutrino masses, and the extreme weakness of Standard Model neutrino interactions, it is extremely unlikely...

"Could be part of it" is just handwaving for "we can't detect any effects of it". In other words, it's pure speculation in the absence of any evidence. Which makes it no better than Carl Sagan's invisible dragon in the garage. The paper considers the hypothesis that dark matter must be mostly...

If ##\hat{A}## represents an observable (and in principle any Hermitian operator can represent an observable), then a state ##\ket{\psi}## that satisfies the eigenvalue equation for ##\hat{A}## will have a definite value for that observable, whereas a state that doesn't satisfy the eigenvalue...

Which are classical models, so they can't possibly say anything about QFT. Yes. Yes.

Having to estimate certain parameters in a classical model using a quantum model is not at all the same as having one's choice of classical model modify QFT. Even choosing which quantum model to use to estimate the classical parameters is not the same as modyfing QFT. The Standard Model is a...

The ##\Lambda C D M## model is a classical model (using classical GR), yes. However, some of the parameters in the model depend on our knowledge of quantum effects, such as the Standard Model predictions for what ratio of isotopes we should expect from Big Bang nucleosynthesis.

As has already been pointed out, the term "time dilation" is ambiguous. The Rindler quote is referring to "time dilation" in the sense of what has been called in this thread "differential aging", and which is invariant and does not depend on any choice of convention. But "time dilation" can also...

I note that one of the authors of this paper is Deur, who has published a number of papers arguing for the presence effects in GR that are not generally accepted or taken into account (and quite a few of them have been discussed in previous PF threads). I don't know if this line of research of...

The Wikipedia article is not saying that the theoretical prediction of Unruh radiation is not disputed. What are disputed, according to the article, are claims to have experimentally observed the effect. Since the effect is extremely tiny for accelerations we can reasonably achieve with our...

I assume you mean contraction with the inverse metric ##g^{\mu \nu}##?