Axion Stars †
Abstract
:1. Introduction
2. Axion Field Theories at Different Energy Scales
3. Axion Stars
3.1. Dilute Axion Stars
3.2. Dense Axion Stars
4. Theoretical Issues
4.1. Emission from Axion Stars
4.2. Collapse of Dilute Axion Stars
- A black hole, with a Schwarzschild radius which is smaller than the critical radius by about 15 orders of magnitude;
- A dense axion star, with a radius which is smaller than by about 7 orders of magnitude;
- A dilute axion star, with a radius which is larger than ; and
- No remnant, because of complete disappearance into scalar waves.
Funding
Conflicts of Interest
References
- Kim, J.E.; Carosi, G. Axions and the strong CP problem. Rev. Mod. Phys. 2010, 82, 557. [Google Scholar] [CrossRef] [Green Version]
- Braaten, E.; Zhang, H. Colloquium: The physics of axion stars. Rev. Mod. Phys. 2019, 91, 41002. [Google Scholar] [CrossRef]
- Arvanitaki, A.; Dimopoulos, S.; Dubovsky, S.; Kaloper, N.; March-Russell, J. String axiverse. Phys. Rev. D 2010, 81, 123530. [Google Scholar] [CrossRef] [Green Version]
- Hu, W.; Barkana, R.; Gruzinov, A. Fuzzy cold dark matter: the wave properties of ultralight particles. Phys. Rev. Lett. 2000, 85, 1158. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Hui, L.; Ostriker, J.P.; Tremaine, S.; Witten, E. Ultralight scalars as cosmological dark matter. Phys. Rev. D 2017, 95, 43541. [Google Scholar] [CrossRef] [Green Version]
- Peccei, R.D.; Quinn, H.R. CP Conservation in the Presence of Instantons. Phys. Rev. Lett. 1977, 38, 1440. [Google Scholar] [CrossRef] [Green Version]
- Weinberg, S. A new light boson? Phys. Rev. Lett. 1978, 40, 223. [Google Scholar] [CrossRef]
- Wilczek, F. Problem of strong P and T invariance in the presence of instantons. Phys. Rev. Lett. 1978, 40, 279. [Google Scholar] [CrossRef]
- di Cortona, G.G.; Hardy, E.; Vega, J.P.; Villadoro, G. The QCD axion, precisely. JHEP 2016, 1601, 34. [Google Scholar] [CrossRef]
- di Vecchia, P.; Veneziano, G. Chiral dynamics in the large N limit. Nucl. Phys. B 1980, 171, 253. [Google Scholar] [CrossRef] [Green Version]
- Bardeen, W.A.; Tye, S.-H.H. Current algebra applied to properties of the light Higgs boson. Phys. Lett. B 1978, 74, 229. [Google Scholar] [CrossRef]
- Peccei, R.D.; Quinn, H.R. Constraints imposed by CP conservation in the presence of pseudoparticles. Phys. Rev. D 1977, 16, 1791. [Google Scholar] [CrossRef]
- Namjoo, M.H.; Guth, A.H.; Kaiser, D.I. Relativistic corrections to nonrelativistic effective field theories. Phys. Rev. D 2018, 98, 16011. [Google Scholar] [CrossRef] [Green Version]
- Braaten, E.; Mohapatra, A.; Zhang, H. Nonrelativistic effective field theory for axions. Phys. Rev. D 2016, 94, 76004. [Google Scholar] [CrossRef] [Green Version]
- Braaten, E.; Mohapatra, A.; Zhang, H. Emission of photons and relativistic axions from axion stars. Phys. Rev. D 2017, 96, 31901. [Google Scholar] [CrossRef] [Green Version]
- Braaten, E.; Mohapatra, A.; Zhang, H. Classical nonrelativistic effective field theories for a real scalar field. Phys. Rev. D 2018, 98, 96012. [Google Scholar] [CrossRef] [Green Version]
- Tkachev, I.I. On the possibility of Bose star formation. Phys. Lett. B 1991, 261, 289. [Google Scholar] [CrossRef]
- Chavanis, P.H. Mass-radius relation of Newtonian self-gravitating Bose-Einstein condensates with short-range interactions: I. Analytical results. Phys. Rev. D 2011, 84, 43531. [Google Scholar] [CrossRef] [Green Version]
- Schiappacasse, E.D.; Hertzberg, M.P. Analysis of dark matter axion clumps with spherical symmetry. JCAP 2018, 1801, 37, Erratum in 2018, 1803, E01. [Google Scholar] [CrossRef] [Green Version]
- Eby, J.; Leembruggen, M.; Street, L.; Suranyi, P.; Wijewardhana, L.C.R. Approximation methods in the study of boson stars. Phys. Rev. D 2018, 98, 123013. [Google Scholar] [CrossRef] [Green Version]
- Kling, F.; Rajaraman, A. Profiles of boson stars with self-interactions. Phys. Rev. D 2018, 97, 63012. [Google Scholar] [CrossRef] [Green Version]
- Braaten, E.; Mohapatra, A.; Zhang, H. Dense Axion Stars. Phys. Rev. Lett. 2016, 117, 121801. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Wang, X.Z. Cold Bose stars: Self-gravitating Bose-Einstein condensates. Phys. Rev. D 2001, 64, 124009. [Google Scholar] [CrossRef]
- Visinelli, L.; Baum, S.; Redondo, J.; Freese, K.; Wilczek, F. Dilute and dense axion stars. Phys. Lett. B 2018, 777, 64. [Google Scholar] [CrossRef]
- Segur, H.; Kruskal, M.D. Nonexistence of small amplitude breather solutions in ϕ4 theory. Phys. Rev. Lett. 1987, 58, 747. [Google Scholar] [CrossRef] [PubMed]
- Fodor, G.; Forgacs, P.; Horvath, Z.; Mezei, M. Radiation of scalar oscillons in 2 and 3 dimensions. Phys. Lett. B 2009, 674, 319. [Google Scholar] [CrossRef] [Green Version]
- Eby, J.; Suranyi, P.; Wijewardhana, L.C.R. The lifetime of axion stars. Mod. Phys. Lett. A 2016, 31, 1650090. [Google Scholar] [CrossRef] [Green Version]
- Mukaida, K.; Takimoto, M.; Yamada, M. On longevity of I-ball/oscillon. JHEP 2017, 1703, 122. [Google Scholar] [CrossRef]
- Eby, J.; Ma, M.; Suranyi, P.; Wijewardhana, L.C.R. Decay of ultralight axion condensates. JHEP 2018, 1801. [Google Scholar] [CrossRef] [Green Version]
- Chavanis, P.H. Collapse of a self-gravitating Bose-Einstein condensate with attractive self-interaction. Phys. Rev. D 2016, 94, 83007. [Google Scholar] [CrossRef] [Green Version]
- Harko, T. Gravitational collapse of Bose-Einstein condensate dark matter halos. Phys. Rev. D 2014, 89, 84040. [Google Scholar] [CrossRef] [Green Version]
- Eby, J.; Leembruggen, M.; Suranyi, P.; Wijewardhana, L.C.R. Collapse of axion stars. JHEP 2016, 1612. [Google Scholar] [CrossRef]
- Eby, J.; Leembruggen, M.; Suranyi, P.; Wijewardhana, L.C.R. QCD axion star collapse with the chiral potential. JHEP 2017, 1706, 14. [Google Scholar] [CrossRef]
- Helfer, T.; Marsh, D.J.E.; Clough, K.; Fairbairn, M.; Lim, E.A.; Becerril, R. Black hole formation from axion stars. JCAP 2017, 1703, 55. [Google Scholar] [CrossRef] [Green Version]
- Levkov, D.G.; Panin, A.G.; Tkachev, I.I. Relativistic axions from collapsing Bose stars. Phys. Rev. Lett. 2017, 118, 11301. [Google Scholar] [CrossRef] [PubMed] [Green Version]
© 2019 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Share and Cite
Zhang, H. Axion Stars. Symmetry 2020, 12, 25. https://doi.org/10.3390/sym12010025
Zhang H. Axion Stars. Symmetry. 2020; 12(1):25. https://doi.org/10.3390/sym12010025
Chicago/Turabian StyleZhang, Hong. 2020. "Axion Stars" Symmetry 12, no. 1: 25. https://doi.org/10.3390/sym12010025
APA StyleZhang, H. (2020). Axion Stars. Symmetry, 12(1), 25. https://doi.org/10.3390/sym12010025