Weakly interacting massive particle annual modulation with opposite phase in late-infall halo models - art. no. 023504

We show that in the late-infall model of our galactic halo of Sikivie the e xpected phase of the annual modulation of a weakly interacting massive part icle (WIMP) halo signal in direct detection experiments is opposite to the one usually expected. If a nonvirialized halo component due to the infall o f (collisionless) dark matter particles cannot be rejected, an annual modul ation in a dark matter signal should be looked for by experimenters without fixing the phase a priori. Moreover, WIMP streams coming to Earth from dir ections above and below the galactic plane should be expected, with a chara cteristic pattern of arrival directions.