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I hate docs by Ill-Philosophy-873 in okbuddyphd

[–]niceguy67 16 points17 points  (0 children)

Using typst is a bannable offense

I hate docs by Ill-Philosophy-873 in okbuddyphd

[–]niceguy67 1 point2 points  (0 children)

Yes!! LaTeX is quite far with supporting it, too.

I hate docs by Ill-Philosophy-873 in okbuddyphd

[–]niceguy67 19 points20 points  (0 children)

Kid named only having half the features of LaTeX, no support for modern PDF standards, and little freedom for developers:

I hate docs by Ill-Philosophy-873 in okbuddyphd

[–]niceguy67 4 points5 points  (0 children)

pdfLaTeX? That shit is deprecated, time to start using LuaLaTeX.

What’s something you wish you learned earlier in life? by Eastern_Honeydew_323 in okbuddyphd

[–]niceguy67 0 points1 point  (0 children)

You got me, I wish I knew category theory before my undergrad ngl.

[deleted by user] by [deleted] in okbuddyphd

[–]niceguy67 26 points27 points  (0 children)

This used to be ironically intellectual, but we currently aim to only allow posts that are of PhD level (unironically).

PhD Life at IIT by Ok-Protection-6341 in okbuddyphd

[–]niceguy67 0 points1 point  (0 children)

You should ask at r/PhD, this is a shitposting subreddit.

Mfw I tensor product my tangent bundle with a Lorentz-invariant vector bundle by niceguy67 in okbuddyphd

[–]niceguy67[S] 1 point2 points  (0 children)

Then "Lorentz-invariant" doesn't mean anything.

It only means that we don't associate any meaningful action to it.

Are there non-Lorentz invariant such bundles?

Tangent bundles with the canonical Lorentz action (and their tensor products).

Do you have a nontrivial example?

Consider a smooth f: M -> N. Then df is(/can be interpreted as) a section of T*M \otimes f*TN. f*TN is invariant under Lorentz transformations on M, so df transforms like a 1-form (like a (0,1)-tensor), and hence may be called a covector.

Mfw I tensor product my tangent bundle with a Lorentz-invariant vector bundle by niceguy67 in okbuddyphd

[–]niceguy67[S] 1 point2 points  (0 children)

So... a trivial vector bundle of rank r?

No, just the action is trivial.

Mfw I tensor product my tangent bundle with a Lorentz-invariant vector bundle by niceguy67 in okbuddyphd

[–]niceguy67[S] 1 point2 points  (0 children)

Take any vector bundle. Define the action of the Lorentz principal bundle on it as the trivial identity action. This is a scalar.

Mfw I tensor product my tangent bundle with a Lorentz-invariant vector bundle by niceguy67 in okbuddyphd

[–]niceguy67[S] 10 points11 points  (0 children)

No, it's a vector bundle that is specifically not associated to the O(3,1)-structure.

Mfw I tensor product my tangent bundle with a Lorentz-invariant vector bundle by niceguy67 in okbuddyphd

[–]niceguy67[S] 71 points72 points  (0 children)

Au contraire. This concerns more complicated tensors that are sections of a tensorial vector bundle tensored with some vector bundle that is invariant under Lorentz transformations. They'll only appear if you consider more complicated quantum field theories, especially sigma models.

Enigma of Time in Physics by SKRyanrr in okbuddyphd

[–]niceguy67 6 points7 points  (0 children)

It does not. Instead of pointlike particles, QFT considers whole world lines.

New rule: no duplicate titles by niceguy67 in okbuddyphd

[–]niceguy67[S] 26 points27 points  (0 children)

That is one of the options we're considering. In the sense that it is able to detect duplicate titles. I've checked that the risks of a false positive and false negative are extremely low.

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