Questions tagged [locality]
The locality tag has no usage guidance.
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Locality and local gauge invariance
I was reading this question on the Physics Stack Exchange, and I'm still not quite sure how I can understand the relationship between locality and local gauge invariance using this example. Consider ...
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How to understand the principle of locality from a common example?
I'm reading the definition of the principle of locality from its Wikipedia page:
The principle of locality states that an object is influenced directly only by its immediate surroundings.
This ...
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Is Gauss law for gravity local?
in Newtonian gravity, the gravitational field obeys the equation
$$\nabla^2 \phi = 4 \pi G \rho$$
David Tong in his notes on general relativity claims that this equation works well when $\rho$ is not ...
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In an entangled system, what happens to Alice's wavefunction right after Bob makes a measurement?
Suppose two entangled particles are far apart. One is with Alice and the other is with Bob. The relative velocity between Alice and Bob is zero (and spacetime is flat), so that we can define a notion ...
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Don't Bell experiments rule out local non-realism too? [duplicate]
Bell experiments rule out local realism (hidden variables). But it seems to me that it also rules out local non-realism (no hidden variables).
Local non-realism makes 2 claims;
Two distant events can'...
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How to tell if a theory is "local"?
Suppose I have a collection of $N$ quantum systems, which I would like to think of as lattice sites. If you tell me that these $N$ sites have some particular embeddings $\vec{x}_i$ in $\mathbb{R}^d$, ...
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Cluster decomposition $\stackrel{?}{=}$ Translation invariance
In Weinberg Volume 1 (section 4.4), Weinberg argues for a certain structure of the interaction Hamiltonian by demanding that it produce an $S$-matrix satisfying cluster decomposition. The proposed ...
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Proof that conservation of momentum is Lorentz invariant
In classical mechanics, if
$$\frac{\mathrm d}{\mathrm d t}\sum_i m_i\vec{v_i}=0$$is true for one frame of reference, then it is easy to prove that this is true for all frames (since different frames ...
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Why is the local component of sound particle-velocity not associated with a local component of pressure?
A sound wave can be described by the pressure field or the sound air particle velocity (acoustic flow). Both are intrinsic to any sounds, i.e. there is no sound wave if no pressure or no particle ...
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How does the many-worlds interpretation solve spooky action at a distance?
If we take the classic example of two particles that are entangled with up spin and down spin, and we separate these particles a few light years apart and then observe them one after the other, they ...
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Is there something that violates "time locality"?
The way I understand locality is that for an object to influence another object away from it, it has to do so through the space that separates them. It can shoot out an EM wave to the other object, ...
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Local nature of physical laws
All the laws in physics are local in nature and that's why their formulation follows differential equations. My doubt is whether the locality is a proven theorem or it is a postulate?
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Is causality a consequence or a constraint in physics?
I wonder if causality is a constraint that we must add to physical models (if needed), or is it a consequence of Lorentz invariance and locality (or something else). In other words, which properties ...
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What are the implications of rejecting the local tomography assumption?
Recently I presented on the paper by Renou, et. al. in Nature (Quantum theory based on real numbers can be experimentally falsified) developing an experimental technique for rejecting real ...
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Local algebra of AQFT vs Bisognano Wichmann Theorem
Maybe I am misunderstanding something really stupid, but I am finding it hard to think of local algebras in terms of wedge algebras. One of the claims (see, e.g., Section 3 and 4 of this paper) is ...
