Baby Universes in the Laboratory

This was on the new books table at our local bookstore. I had almost forgotten about doing an interview and corresponding with the author some time ago. See also here and here. The book is a well-written overview of some of the more theoretical aspects of inflationary cosmology, the big bang, the multiverse, etc. It also …

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Astrophysical Repulsion from Dark Energy

The manifestation of dark energy on cosmological scales is well known: gravitational repulsion which leads to the accelerating expansion of the universe. Perhaps surprisingly, there are potentially observable effects on galactic length scales as well. The Dark Force: Astrophysical Repulsion from Dark Energy (http://arxiv.org/abs/1501.05952) Chiu Man Ho, Stephen D. H. Hsu Dark energy (i.e., a cosmological …

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Instability of Quantum de Sitter Spacetime

New paper! We show that quantum effects (in particular, the horizon temperature originally discovered by Gibbons and Hawking) modify the geometry of de Sitter spacetime. Instability of Quantum de Sitter Spacetime (http://arxiv.org/abs/1501.00708) Chiu Man Ho, Stephen D. H. Hsu Quantized fields (e.g., the graviton itself) in de Sitter (dS) spacetime lead to particle production: specifically, …

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Implications of cosmological tensor modes

New paper! What can we conclude about high energy physics from the BICEP2 observations of a cosmological tensor mode background? See earlier post Patterns on the Sky. Does the BICEP2 Observation of Cosmological Tensor Modes Imply an Era of Nearly Planckian Energy Densities?  (arXiv:1404.0745) Chiu Man Ho, Stephen D. H. Hsu BICEP2 observations, interpreted most …

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Patterns on the sky

I’m busy reviewing ~200 promotion and tenure cases for my day job, so I don’t have much time to post about the BICEP2 observation of primordial gravitational waves via their effect on the polarization of the cosmic microwave background (CMB). Instead, I refer you to Sean Carroll, Lubos Motl and Liam McAllister (guest poster at …

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