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19 votes
1 answer
2k views

When do real analytic functions form a coherent sheaf?

It is known that, in general, the sheaf of real analytic functions on a real analytic manifold is not coherent. However, there are some examples, where we have coherence: for example, if $X$ is a ...
Grisha Papayanov's user avatar
5 votes
2 answers
529 views

When is a real-analytic variety a union of non-singular subvarieties?

I have asked this before on MSE, but received no answer yet. Say I have a set in $\mathbb{R}^n$ defined to be the zero set of an analytic function $F:\mathbb{R}^n\to\mathbb{R}^k$, $k<n$. Everywhere,...
nicrot000's user avatar
  • 212
4 votes
1 answer
440 views

Origin of 'Analytic' Geometry?

My impression is that the name analytic geometry, which I understand roughly to be geometry in Euclidean space using coordinates, is not used that much anymore. We would probably classify the subject ...
Minhyong Kim's user avatar
  • 13.4k
4 votes
0 answers
159 views

Sheaf of smooth functions and restriction to a divisor

My question is targeted towards a very particular detail in my research that I am trying to understand. I will therefore break it down into some more general questions. Let $X$ be a smooth variety, $i:...
Arkadij's user avatar
  • 914
3 votes
2 answers
588 views

If $K$ and $L$ are compact convex sets with smooth boundary, does their union have piecewise-smooth boundary?

Clarification: by "piecewise", I mean a finite number of pieces. I'm sure this must be true, but my search for a citation was in vain (although I did learn the new term "polyconvex"). Thanks!
Ryan O'Donnell's user avatar
3 votes
1 answer
384 views

about transverse complete intersection

There are several questions about transverse complete intersection arising from L. Guth's paper: http://www.ams.org/journals/jams/0000-000-00/S0894-0347-2015-00827-X/home.html We say a polynomial $P$...
ZTD's user avatar
  • 103
2 votes
1 answer
343 views

Is the closure of an open holomorphically convex subset of a Stein space holomorphically convex?

Let X be a Stein manifold and U an open, connected, relatively compact, holomorphically convex subset of X. Is the closure of U in X holomorphically convex? Also, if X is a Stein space with a finite ...
user3566's user avatar
  • 169