Interactions in the dark sector of the Universe
  Interactions inside the cosmological dark sector influence the cosmological dynamics. As a consequence, the future evolution of the Universe may be different from that predicted by the $\Lambda$CDM model. We review main features of several recently studied models with nongravitational couplings between dark matter and dark energy. 
W. Zimdahl
astro-ph.CO gr-qc hep-th