Massive Compact Halo Objects from the Relics of the Cosmic Quark-Hadron   Transition
  The existence of compact gravitational lenses, with masses around 0.5 (M_{\odot}), has been reported in the halo of the Milky Way. The nature of these dark lenses is as yet obscure, particularly because these objects have masses well above the threshold for nuclear fusion. In this work, we show that they find a natural explanation as being the evolutionary product of the metastable false vacuum domains (the so-called strange quark nuggets) formed in a first order cosmic quark-hadron transition. 
Shibaji Banerjee, Abhijit Bhattacharyya, Sanjay K. Ghosh, Sibaji Raha.   Bikash Sinha and Hiroshi Toki