Portal de Periódicos da CAPES

Cosmological limits on deviations from φ 2 potentials in oscillating scalar cold dark matter models

1993; American Physical Society; Volume: 48; Issue: 6 Linguagem: Inglês

10.1103/physrevd.48.2573

1538-4500

J. McDonald,

Particle physics theoretical and experimental studies

We consider the consequences for oscillating scalar cold dark matter models of a scalar field \ensuremath{\varphi} which oscillates in a potential which deviates slightly from a ${\mathrm{\ensuremath{\varphi}}}^{2}$ potential. We consider a correction to the ${\mathrm{\ensuremath{\varphi}}}^{2}$ potential of the form K${\mathrm{\ensuremath{\varphi}}}^{2}$ln(${\mathrm{\ensuremath{\varphi}}}^{2}$)+${\ensuremath{\lambda}}_{\mathrm{\ensuremath{\varphi}}}$${\mathrm{\ensuremath{\varphi}}}^{4}$. Upper bounds on \ensuremath{\Vert}K\ensuremath{\Vert} and \ensuremath{\Vert}${\ensuremath{\lambda}}_{\mathrm{\ensuremath{\varphi}}}$\ensuremath{\Vert} are obtained as a function of the \ensuremath{\varphi} mass by requiring that the effects of the pressure introduced by the correction to the potential do not disrupt the conventional cold dark matter scenario for structure formation. The results are applied to some cosmological models of recent interest. In particular, it is shown that a scalar identified with the pseudo Goldstone boson of a U(1) symmetry explicitly broken by neutrino masses (suggested in connection with late-time phase transitions) is inconsistent with the MSW solution of the solar neutrino problem if it is to account for dark matter. In addition it is shown that a cold dark matter model in which the Compton wavelength of a very light scalar particle accounts for the large-scale structure of the Universe is also ruled out by the effects of pressure on structure formation.