Orodruin's latest activity
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<<Emphasis added.>> I don't see how the application process in the EU vs the US resembles each other here. There is a big advantage to... -
Orodruin replied to the thread Schools Hepth programs in Europe.Not only is a Master’s degree helpful, it is often a prerequisite to be eligible for a European PhD program. (Local variations apply...
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Orodruin replied to the thread I Intrinsic curvature.Planes, I agree, but not with a single ball, which was my understanding from the discussion.
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Orodruin replied to the thread I Intrinsic curvature.I believe that is intrinsically applying the Levi-Civita connection as the geodesics of the Levi-Civita connection are the paths that...
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Orodruin replied to the thread I Intrinsic curvature.Not only why, but ”you cannot”. It is impossible to do it without parallel transport - or at least without parallel transport being...
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The tangent space at a point is not a plane in the 3D embedding space (although that is a natural way of visualizing it, continuing our...
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Orodruin replied to the thread B Matter density right after the decoupling.Free-streaming means that the (average) density of matter is so small that the mean-free path exceeds the size of the Universe. The...
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Orodruin replied to the thread I Question about Parallel Transport.I mean, it is a two-dimensional gyroscope, i.e., one where the gyroscope is only free to rotate around one axis ... :wink: I'd like to...
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Orodruin replied to the thread I Question about Parallel Transport.The FW transport in GR is the correct thing to use for gyroscopes precisely because we are talking about its frame describing spacelike...
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I disagree. The definition of a geodesics as a curve that parallel transports its tangent vector makes no sense without parallel...
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Orodruin replied to the thread B Matter density right after the decoupling.Compare to the density of the Sun's photosphere. The number density of hydrogen there is about ##10^{24}## per cubic meter. But of...
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Orodruin replied to the thread I Question about Parallel Transport.The entire point of FW transport is to keep a spacelike vector, such as a polarization vector, orthogonal to the timelike tangent of the...
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Orodruin replied to the thread I Question about Parallel Transport.The Levi-Civita connection is the unique metric compatible and torsion free connection on a Riemannian manifold (or pseudo-Riemannian)...
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Orodruin replied to the thread I Question about Parallel Transport.Parallel transport is perfectly well defined along non-geodesic curves. The manifold described in the video is a Riemannian manifold so...
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Orodruin replied to the thread I Question about Parallel Transport.No, definitely not. There should be no outside reference. If he walks straight forward, he keeps the arrow in the same direction...
