Cosmic Bose dark matter

It is known that cold and hot dark matter imprint opposed effects on the cosmological observables; naturally, it is often thought that they should be made of different kinds of particles. We point out, however, that a Bose-Einstein condensate could be the source of both components. In this framework, the mass and temperature constraints on hot dark matter contain fundamental information of cold dark matter. We discuss two scenarios: a gas made of bosons and a gas made of boson-antiboson pairs. We obtain constraints on the bosonic dark matter parameters from cosmological data and test the idea by probing the condition on the critical temperature of condensation, including a forecast for the Planck mission. We find that the bosonic dark matter picture is consistent with data in the boson scenario, while the boson-antiboson scenario might be increasingly interesting for future data surveys.