We give an asymptotic formula for the number of quartic extensions of a function field with discriminant equal to some bound, essentially reproducing the analogous result over number fields due Cohen, Diaz y Diaz, and Olivier, but with a stronger error term. We also study the relative density of and quartic extensions of a function field and show that with mild conditions, the number of quartic extensions can far exceed the number of quartic extensions.
Nous donnons une formule asymptotique pour le nombre d’extensions quartiques du type et de discriminant donné d’un corps de fonctions en démontrant un résultat analogue à celui de Cohen, Diaz y Diaz et Olivier pour les corps de nombres mais avec un meilleur terme d’erreur. Nous étudions aussi la densité relative des extensions quartiques des types et d’un corps de fonctions. Nous montrons que sous des hypothèses faibles, le nombre d’extensions quartiques du type peut largement dépasser le nombre d’extensions quartiques du type .
Accepted:
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Keywords: Field counting, function fields, Galois theory, polynomials
@article{JTNB_2022__34_2_371_0, author = {Keliher, Daniel}, title = {Enumerating $D_4$ quartics and a {Galois} group bias over function fields}, journal = {Journal de th\'eorie des nombres de Bordeaux}, pages = {371--391}, publisher = {Soci\'et\'e Arithm\'etique de Bordeaux}, volume = {34}, number = {2}, year = {2022}, doi = {10.5802/jtnb.1206}, language = {en}, url = {http://www.numdam.org/articles/10.5802/jtnb.1206/} }
TY - JOUR AU - Keliher, Daniel TI - Enumerating $D_4$ quartics and a Galois group bias over function fields JO - Journal de théorie des nombres de Bordeaux PY - 2022 SP - 371 EP - 391 VL - 34 IS - 2 PB - Société Arithmétique de Bordeaux UR - http://www.numdam.org/articles/10.5802/jtnb.1206/ DO - 10.5802/jtnb.1206 LA - en ID - JTNB_2022__34_2_371_0 ER -
%0 Journal Article %A Keliher, Daniel %T Enumerating $D_4$ quartics and a Galois group bias over function fields %J Journal de théorie des nombres de Bordeaux %D 2022 %P 371-391 %V 34 %N 2 %I Société Arithmétique de Bordeaux %U http://www.numdam.org/articles/10.5802/jtnb.1206/ %R 10.5802/jtnb.1206 %G en %F JTNB_2022__34_2_371_0
Keliher, Daniel. Enumerating $D_4$ quartics and a Galois group bias over function fields. Journal de théorie des nombres de Bordeaux, Volume 34 (2022) no. 2, pp. 371-391. doi : 10.5802/jtnb.1206. http://www.numdam.org/articles/10.5802/jtnb.1206/
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