  First a review of Teleparallel theory is done with special emphasis in the
derivation of conservation equations within this theory and in particular of
energy-momentum conservation. Given that we are allowed to speak about the
existence of negative energy, the question is that in its interaction with
matter, we need not have matter conservation: It is only the sum of both which
should remain constant. This does not only leads to an accelerated expansion
without the need of a cosmological constant, but it may also contribute to
explain the origin of dark matter, and poses questions about the origin of
inflation at earlier times. The prediction of the proposed model can be
qualitatively compared to recent results of Cosmic Microwave Background (CMB)
analysis.
