Binary Quadratic Forms and Counterexamples to Hasse's Local-Global Principle
arXiv:1108.5687
Abstract
After a brief introduction to the classical theory of binary quadratic forms we use these results for proving (most of) the claims made by Pépin in a series of articles on unsolvable quartic diophantine equations, and for constructing families of counterexamples to the Hasse Principle for curves of genus 1 defined by equations of the form .