Large Tate--Shafarevich orders from good $abc$ triples
Number Theory
2021-11-16 v1
Abstract
Record values are determined for the order of the Tate--Shafarevich group of an elliptic curve , computed analytically by the Birch--Swinnerton-Dyer conjecture, and for the Goldfeld--Szpiro ratio , where is the conductor of . The curves have rank zero and are isogenous to quadratic twists of Frey curves constructed from coprime positive integers with and , where the radical is the product of the primes dividing . Curves with and are found in 20 isogeny classes. Three curves have . The largest value of is . This is more than 3.5 times the previous record, which had been computed at a cost about 600 times greater than that for the new record. The primes 25913, 27457, 36929 and 49253 are identified as divisors of values.
Cite
@article{arxiv.2111.07794,
title = {Large Tate--Shafarevich orders from good $abc$ triples},
author = {David Broadhurst},
journal= {arXiv preprint arXiv:2111.07794},
year = {2021}
}
Comments
17 pages