25m revised Stuck at a proof with integralsedited tags 18h awarded Good Question Dec 7 awarded Disciplined Dec 6 answered finding the number of sub fields such that $(K : Q) = 2$ Nov 16 awarded Supporter Oct 23 awarded Nice Answer Oct 22 comment If $A$ is an $R$-module with some sort of ring structure, is it true that any $R$-submodule of $A$ is an ideal of $A$?If you think of the ring $R$ as an $R$-module, with scalar multiplication being the usual multiplication in $R$, then in that case yes, all the submodules are precisely the ideals of $R$. Oct 18 answered Does $\sum_{n=1}^{\infty} \sin\left(\frac{\pi}{n}\right)$ converge? Oct 13 comment If $f(x)g(x) = x$, then is it possible that $f$ and $g$ are differentiable and $f(0)=g(0)=0$?Intuitively this is the observation that $f(x)g(x)$ vanishes to order at least two at $0$, whereas $h(x) = x$ only vanishes to order one at $0$. Oct 11 comment The number of Number Fields of discriminant less than or equal to a particular value@user30535 Maybe this could be of help? Oct 10 comment Question about the definition of the genus 0 curves in Gross' paper "Heights and the Special values of L-series"@Daniel Thanks for the reference, indeed it looks like what I need to understand in in there. Oct 10 comment Question about the definition of the genus 0 curves in Gross' paper "Heights and the Special values of L-series"@Marguax Thanks a lot for your comments. Do you know a reference where I can consult those definitions about the trace and norm? Oct 10 accepted Question about the definition of the genus 0 curves in Gross' paper "Heights and the Special values of L-series" Oct 10 comment Question about the definition of the genus 0 curves in Gross' paper "Heights and the Special values of L-series"Thank you very much Felipe. Oct 10 asked Question about the definition of the genus 0 curves in Gross' paper "Heights and the Special values of L-series" Oct 8 answered An 'obvious' property of algebraic integers? Oct 8 awarded Constituent Oct 8 awarded Caucus Oct 7 revised When is $\sum_{k=1}^{\infty}a(k) \sum_{k=1}^{\infty}b(k)\ge \sum _{k=1}^{\infty}a(k)b(k)?$edited title Oct 7 comment Galois theory problem.Alex, I think that in your second bullet point, on the third line, one of your quadratic extensions should be $L' = k(\sqrt{v})$ for instance. Right now you have $L$ for both.