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9 votes
1 answer
946 views

What is the etymology of the mathematical terms "sheaf, stalk, germ"?

The peculiar agricultural terminology commonly used in algebraic geometry and category theory, "sheaf", "stalk", "germ", is quite well-known. A sheaf is pictured as something like a bundle of stalks, ...
Todd Trimble's user avatar
3 votes
1 answer
435 views

When was a partition of unity discovered?

A partition of unity is a mathematical concept in geometry. I want to know when and in what context this concept appeared.
user avatar
0 votes
1 answer
116 views

on the classification of singular points

After reading this question and the answers to it, I am interested o know who were the first mathematicians who started classifying singular points of curves: i.e. different kind of nodes, of cusps ...
David's user avatar
  • 293
5 votes
1 answer
1k views

What is the origin of the use of "g" for a Riemannian metric?

I am asking about the reason for the use of this letter, if known, as well as the initial occasion of its use. Ideas that have been suggested concerning the former include: That it stands for ...
Archelon's user avatar
  • 163
6 votes
0 answers
309 views

Is $\Gamma^i_{jk}$ the Christoffel symbol or the Christoffel symbols?

For years, I have been perplexed that the expression $\Gamma^i_{jk}$ is often referred to in the plural as "the Christoffel symbols", although sometimes it is referred to in the singular as "the ...
Alan U. Kennington's user avatar
10 votes
4 answers
1k views

Was the term "manifold" (or its German equivalent) chosen with the verb "to fold" in mind?

Recently I came across several papers of Monge and Lagrange, around the end of the 18th century, considering developable surface as 'folded' planes, using specifically the word "plié" (i.e. folded). ...
David's user avatar
  • 153
7 votes
1 answer
1k views

How did the 'Poincaré patches' get their name?

De Sitter space and Anti de Sitter space are two of the most important solutions to the Einstein field equations. One famous method to obtain these spacetimes is to consider a $N$-dimensional ...
Danu's user avatar
  • 3,891