http://arxiv.org/abs/1507.05760 Higgs boson cosmology Ian G. Moss (Submitted on 21 Jul 2015) The discovery of the Standard Model Higgs boson opens up a range of speculative cosmological scenarios, from the formation of structure in the early universe immediately after the big bang, to relics from the electroweak phase transition one nanosecond after the big bang, on to the end of the present-day universe through vacuum decay. Higgs physics is wide-ranging, and gives an impetus to go beyond the Standard Models of particle physics and cosmology to explore the physics of ultra-high energies and quantum gravity. This is an interesting review of topics like Higgs inflation and the effects of the electroweak phase transition. But what's really news to me is the claim on page 12 that "the metastable Higgs vacuum is inconsistent with the existence of even a single primordial black [hole of mass 10^12 Kg] in our observable universe". The fact that the Higgs mass and the top mass place the standard model Higgs vacuum on the edge of metastability may be THE biggest clue about BSM physics that the LHC has given us. The reason for this near-metastability remains completely unknown, and there is also disagreement as to whether the vacuum is metastable (i.e. whether we are living in a false vacuum that will decay one day), or just close to the edge, but nonetheless stable. If metastability of the vacuum is in radical tension with the expected formation of primordial black holes, that's a very big hint about how not to interpret this clue. But how clear-cut is the contradiction?