4 papers
Torsion points on -type abelian varieties
Jessica Alessandrì, Nirvana Coppola
It is well known that the rational torsion of an abelian variety defined over a number field injects into the reduction modulo any sufficiently large prime, so the order of the tor…
On the local-global principle for twists of abelian varieties and Galois representations
Nirvana Coppola, Lorenzo La Porta, Matteo Longo
This paper investigates the validity of a local-global principle for finite twists of a large class of objects endowed with a continuous action of the absolute Galois group of a gi…
Geometrically simple counterexamples to a local-global principle for quadratic twists
Emiliano Ambrosi, Nirvana Coppola, Francesc Fité
Two abelian varieties and over a number field are said to be strongly locally quadratic twists if they are quadratic twists at every completion of . While it was kno…
Wild Galois representations: elliptic curves with wild cyclic reduction
Nirvana Coppola
In 1990, Kraus classified all possible inertia images of the -adic Galois representation attached to an elliptic curve over a non-archimedean local field. In previous work, t…