Skip to main content
1 of 2
Peter Scholze
  • 21.3k
  • 4
  • 104
  • 122

Fontaine-Mazur for GL_1

For any number field $K$, the Fontaine-Mazur conjecture predicts that any potentially semistable $p$-adic representation of the absolute Galois group $G_K$ of $K$ that is almost everywhere unramified is geometric. As far as I can see, the only cases where any progress has been made concerns the case that $K$ is totally real or CM.

This made me wonder: Is the Fontaine-Mazur conjecture known to be true for $1$-dimensional representations for any number field $K$? For CM fields, the theory of CM abelian varieties gives varieties whose cohomology realizes nontrivial characters (and I guess that easy variations should produce all characters). What are the geometric objects appearing for other fields?

Peter Scholze
  • 21.3k
  • 4
  • 104
  • 122