Presheaves and Sheaves

[aminsheykh]

This was a very good explanation. Thanks for saving me my time.

[romdotdog]

This helped me finally understand sheafs after struggling with it for a day. Thank you so much!!!!

[MyGeekAdventures]

Wow, that was remarkably clear - thank you! I've struggled with sheafs and presheafs for a while now, and this really helped bring the abstract notions together.

[craploadofexamples]

This is the best explanation of this concept I’ve ever seen.

[subhamjaiswal]

1:58 u say 'if something is differentiable on V then it's obviously differentiable on U'
I think you meant to say the opposite.

[fbkintanar]

A nicely intuitive explanation of contravariance of restriction maps in the presheaf functor. When I first met the sheaf conditions, they seemed a bit out of the blue, arbitrary, unmotivated. I'm not coming from analysis, but from model-theoretic and categorical logic.

[albertogarcia]

I understand a presheaf F is a contravariant functor from the category of the topological spaces Top to the category of abelian groups Ab. At 7:47 what do you mean with s/U_alpha?. Notice it should be an element of some abelian group.

[ghazan]

wao nice way to explain the concept of sheaf...,

[InquilineKea]

why are restiction maps "restrictions"?

[vinbo]

May I ask why the presheaf of bounded functions must be constant, please?

[rostislavsvoboda]

I can't help myself but all I see at 14:16 is just a circle crossing a line at a specific point but no skyscraper near or far. Can someone explain how to look at it please?

[zavvie]

at 11:40 we have to limit ourselves to holomorphic/entire functions or something

[Sunlessmage]

Hi, under which series does this belong ?