2012/11/09 by Najman, Filip · 2 citations
#11G05 #11G18 #FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.1211.2188
We classify the possible torsion structures of rational elliptic curves over cubic fields. Along the way we find a previously unknown torsion structure over a cubic field, \Z /21 \Z, which corresponds to a sporadic point on X1(21) of degree 3, which is the lowest possible degree of a sporadic point on a modular curve X1(n).