2017/01/31 by S. Shajidul Haque, Bret Underwood · 4 citations
Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Bubble #COSMIC cancer database #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Formalism (music) #Mechanics #Metric expansion of space #Physics #Quantum mechanics #Schwarzschild radius #Solar and Space Plasma Dynamics #Spacetime #Theoretical physics #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.95.103513
published in Physical review. D/Physical review. D. 95(10) (American Physical Society) · 9 pages, 4 figures. v2: updated references. v3: matches published version
openalex publication_date 2017/05/24 · arxiv created 2017/05/31 · arxiv updated 2017/06/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The Raychaudhuri equation for null rays is a powerful tool for finding consistent embeddings of cosmological bubbles in a background spacetime in a way that is largely independent of the matter content. We find that spatially flat or positively curved thin wall bubbles surrounded by a cosmological background must have a Hubble expansion that is either contracting or expanding slower than the background, which is a more stringent constraint than those obtained by the usual Israel thin-wall formalism. Similarly, a cosmological bubble surrounded by Schwarzschild space, occasionally used as a simple ``swiss cheese'' model of inhomogenities in an expanding universe, must be contracting (for spatially flat and positively curved bubbles) and bounded in size by the apparent horizon.