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Intuition about $\mathrm{Spec}\mathbb{C}[[t]]$ versus $\mathrm{Spf}\mathbb{C}[[t]]$ versus $\mathrm{Specan}\mathbb{C}[[t]]$ (and similar objects)
In adic spaces, I believe analytic can refer to points associated to valuations whose kernel is not open in the topology of the ring. But I don't know whether that is the referent in this case. I don't like the terminology though. It gives me incredible urgers to define $\mathrm{Swalnut}\mathbb{C}[[t]], \mathrm{Spumpkin}\mathbb{C}[[t]], \ldots$
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Which mathematicians have influenced you the most?
Wise words from Grothendieck, "A good mathematician always soaks his nuts while trying to solve a problem."
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How to explain to an engineer what algebraic geometry is?
@ArunDebray With all respect to Mumford, his great expertise in the practice of algebraic geometry did not carry over to expertise in the explanation of algebraic geometry to non-mathematicians. It seems like his idea of a non-mathematician is someone who has at the very least a college degree or graduate degree in math or physics, but may not professionally practice math.
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Replacing Spectrum with Valuations of a Field - An Alternative to Schemes?
@EugeneEisenstein +1 for seconding Chandan's appreciation for the recommendation of Borger's viewpoint.
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How does the parity of $n$ affect the properties of $\mathbb{R}^n$?
This sounds like a great premise for a new Saw-like horror movie. A group of strangers wake up in a dark, empty space. They need to determine the dimension of the ambient space, but their time is running out!
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Ostrowski's Theorem for topological rings?
Would someone be willing to write the gist of the Mutylin's construction? The relevant pages of the google book are unavailable to me.
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Explicit family of number rings $\mathcal{O}_{K_n}$ requiring $n$ generators?
Thank you, Professor Conrad. I was familiar with that previous post, and your answer here will make a good complement.
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Does a countably generated $\mathbb{Q}$-algebra inject into some $p$-adic field?
I'm sure all of you are familiar, but for reference, the finitely generated case is covered by the Cassels embedding theorem, which ensures an embedding into infinitely many $\mathbb{Q}_p$.
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Cohen structure theorem with explicit equations
This is related to Weierstrass preparation, correct? Yes, I understand the argument, but I would like to have more knowledge/control of the unit $u$ that can be factored off $b$.
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Is there a graph with 99 vertices in which every edge belong to a unique triangle and every nonedge to a unique quadrilateral?
I've got 99 vertices, but an edge ain't one.
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The different gradings of a graded ring, and their schemes
Some more good info is in Ottem's answer here: mathoverflow.net/questions/47682/….
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The different gradings of a graded ring, and their schemes
For starters, there's en.wikipedia.org/wiki/Weighted_projective_space and also the fact that the Veronese embedding exhibits a number of different gradings with isomorphic scheme structures, namely that scaling and shifting the grading unaffect the result.
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How much reading do you do before you attack a problem?
Using the nuanced insight of @DeaneYang, we can simplify many known results: Let $p$ be a prime. Is there an expression $p = a^2 + b^2$ as a sum of squares? It depends. QED
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Almost but not quite a homomorphism
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Are the integers a vector space or algebra over "some" field or over "some" ring?
The coefficients of the expansion are only unique up to a choice of representatives for $\mathbb{Z}/b\mathbb{Z}$, and the base expansions themselves are a result of the fact that $\mathbb{Z}$ is a discrete valuation ring, for various valuations.
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