Questions tagged [function-fields]
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97 questions
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Why is the Goss plane defined as it is on 1-units?
I am reading the preprint by Kramer-Miller and Upton on zeros of the Goss zeta function, and I am wondering why the Goss plane is defined the way it is.
For $K$ a global function field of ...
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Shimura reciprocity for Drinfeld modular varieties?
let's suppose we have a function field $F$ and some Drinfeld modular variety of rank $r$ over $F$, with some level structure $Y^{(r)}(N)$. Then the field of constants of $Y^{(r)}(N)$ is some class ...
2
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Are there known necessary conditions for when a function field automorphism extends to an automorphism of its completion?
Given a function field $K$ over $\Bbb C$ with a discrete valuation $v$, are there known criteria under which an automorphism of $K$ extends to the completion $K_v$?
I’m aware of sufficient conditions ...
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$\mathbb{Z}_p^{\mathbb{N}}$-extension and formal Drinfeld module
Thanks for your help. I'm reading the paper Iwasawa main conjecture for the Carlitz cyclotomic extension and applications (https://arxiv.org/pdf/1412.5957). I find three questions about the motivation ...
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Why is the category of Weil-étale sheaves abelian with enough injectives?
When I study Weil-étale cohomology put forward by S. Lichtenbaum in the paper The Weil-étale topology on schemes over finite fields, I find two questions.
Let $X$ be a scheme of finite type over a ...
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How could we get the Weil group for global function fields?
Thanks for your help. I know the definition of Weil group and how to get it for $p$-adic local field cases. By reading the answer https://math.stackexchange.com/a/2898449/1007843, I write down my ...
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Specifying Dirichlet characters over global function fields
What is the minimal information needed to specify a Dirichlet character over the function field of a curve over a finite field?
Over $ \mathbb{Q} $, a Dirichlet character is equivalent to a ...
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Request for references on algebraic groups for Drinfeld modules
I am a beginner in research on Drinfeld modules. I have read the recent textbook by Papikian and am now starting to study Goss’s textbook and Anderson’s seminal paper on
$t$-motives.
However, I find ...
7
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Introductory references on curves over finite fields
In many papers on the function fields, it is commonly assumed that a curve is smooth, projective, and geometrically connected over a finite field. Could you please recommend the easiest (shortest) ...
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Proposition 6.2.7 from Goss
I'm following David Goss's book Basic structures of function field arithmetic. Let $L$ be an extension field of $L_0$ and $\sigma$ an automorphism of infinite order which fixes $L_0$. Let $L\{\sigma\}$...
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Cancellation in correlations of the Möbius function over function fields
Let $p$ be an odd prime and $q$ a power of $p$. For a polynomial $f \in \mathbb{F}_q[T]$, let $\mu(f)$ be the Möbius function of $f$. For a positive integer $d$, let $M_d$ be the set of monic ...
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Proposition 6.2.3 from Goss "Basic Structures of Function Field Arithmetic"
I'm studying Proposition 6.2.3 from Goss "Basic Structures of Function Field Arithmetic", page 184:
Let $F$ be the sheaf of Data A (a torsion-free coherent $O_{\bar{X}}$-module on $\bar{X}$ ...
2
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Arithmetic interest of the Goss zeta function
I'm someone with more of a number fields background who recently started working on a project more in the function fields setting. I was reading Goss's book (Basic structures of function field ...
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On the complexity of global fields isomorphism
Let $L$ and $K$ be isomorphic global fields (i.e. either function fields of curves over a finite field, or number fields). What is the complexity of finding an isomorphism between them? Is there a ...
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Degeneracy maps of Drinfeld modular curves
Over number fields, we have two natural degeneracy maps
$$X_0(N)\leftarrow X_0(pN) \rightarrow X_0(N)$$
between the (compactified) moduli space of elliptic curves with level $pN$ and $N$ respectively (...