All Questions
10
questions
1
vote
1
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What does it mean to say the universe is not locally real? [duplicate]
Pardon me if this is a naive question.
What is difference between saying space-time is not locally real, and saying it is not real?
The proposal that the universe is not locally real seems to imply ...
- 231
0
votes
1
answer
67
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Euclidean view in curved manifold
Let's suppose I am an ant who lives in a 2D curved space. Locally the world seems 2d-euclidean to me, but it is not if I consider a large portion of space.
Now let's consider a human being who lives ...
- 719
3
votes
2
answers
232
views
Could there exist a "locality" field? [closed]
What I mean is (and I'm a layperson on the subject), can there exist a field that pervades the universe - like the Higgs field - that interacts with particles to give them "distance" or "space" ...
- 41
2
votes
0
answers
99
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Locality and relativity - a paradox?
The equations of nature are supposed to exhibit locality in the sense that the action depends on fields and their derivatives. i.e. comparing the values of fields at local points.
But two points on a ...
user84158
1
vote
1
answer
132
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Basic question about local algebras in AQFT
AQFT (algebraic quantum field theory) assigns "local algebras of observables" to bounded regions of spacetime, in particular to double-cone ("diamond") regions. These algebras' projection operators ...
- 163
3
votes
0
answers
322
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Malament theorem in curved spacetime?
Malament's theorem roughly assert that given a very general theory of a point particle, characterized by some operator $P_D$ such that for a region of space $D$ at a given time $t$, $P_D | \Psi \...
- 16.5k
4
votes
2
answers
296
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Geometry and integral laws of physics
Reading the English translation of Einstein's seminal paper on GR.
http://einsteinpapers.press.princeton.edu/vol6-trans/90?ajax
This paragraph below on p78 doesn't make much sense to me.
Could you ...
user56963
5
votes
1
answer
613
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Coincidence of spacetime events & Lorentz invariance
Am I correct in thinking that if two spacetime events are coincident in one frame of reference, then they are coincident in all frames of reference, i.e. coincidence of spacetime events is a Lorentz ...
- 3,063
8
votes
2
answers
4k
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Commutation relations in QFT and the principle of locality
My question is, given two space-time points $x^{\mu}$ and $y^{\mu}$, if the events that occur at these points are simultaneous, i.e. $x^{0}=y^{0}$, are the two events necessarily space-like separated? ...
- 3,063
0
votes
1
answer
302
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Is gravity instantaneous? [duplicate]
I want to know if (hypothetically) a star appears out of nowhere at a certain distance (say 20 light seconds) away from me, how long will it take for me to get the feel of it's gravity? Will I know it ...
- 141