Let $L/K$ be a finite Galois extension of number fields that is ramified exactly at one finite prime and is unramified at all infinite primes. Let $U_K$ and $U_L$ denote the units of the ring of integers of $K$ and $L$, respectively. Some examples show that the norm map on units $Norm_{L^*/K^*}: U_L \rightarrow U_K$ is surjective, or equivalently zeroth Tate cohomology of the group $G$ with coefficients in $U_L$ is $0$. Does this surjectivity of the norm map remain true in general for such extensions?
Surjectivity of the norm of units in Galois extensions ramified exactly at one finite prime
Ehsan Shahoseini
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