Lloc: Aula Pere Pascual (507).Facultat de Física
Ordinarily, a scalar field may only play the role of dark energy if it possesses a potential that is either extraordinarily flat or extremely fine-tuned. I shall demonstrate that these restrictions need not apply if the scalar field exchanges energy with another fluid. In this scenario, the field may come to rest while displaced from the local minimum of its potential. As a result, any scalar field is capable of forming dark energy, regardless of the shape of its potential. I will present a physically motivated realisation in the form of a derivative neutrino-majoron coupling.