Abstract
Following Ruffini and Bonazzola, we use a quantized boson field to describe condensates of axions forming compact objects. Without substantial modifications, the method can only be applied to axions with decay constant, f a , satisfying δ = (f a /M P )2 ≪ 1, where M P is the Planck mass. Similarly, the applicability of the Ruffini-Bonazzola method to axion stars also requires that the relative binding energy of axions satisfies \( \varDelta =\sqrt{1-{\left({E}_a/{m}_a\right)}^2}\ll 1 \), where E a and m a are the energy and mass of the axion. The simultaneous expansion of the equations of motion in δ and Δ leads to a simplified set of equations, depending only on the parameter, \( \lambda =\sqrt{\delta }/\varDelta \) in leading order of the expansions. Keeping leading order in Δ is equivalent to the infrared limit, in which only relevant and marginal terms contribute to the equations of motion. The number of axions in the star is uniquely determined by λ. Numerical solutions are found in a wide range of λ. At small λ the mass and radius of the axion star rise linearly with λ. While at larger λ the radius of the star continues to rise, the mass of the star, M , attains a maximum at λmax ≃ 0.58. All stars are unstable for λ > λmax. We discuss the relationship of our results to current observational constraints on dark matter and the phenomenology of Fast Radio Bursts.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
D.J. Kaup, Klein-Gordon geon, Phys. Rev. 172 (1968) 1331 [INSPIRE].
R. Ruffini and S. Bonazzola, Systems of selfgravitating particles in general relativity and the concept of an equation of state, Phys. Rev. 187 (1969) 1767 [INSPIRE].
M. Colpi, S.L. Shapiro and I. Wasserman, Boson stars: gravitational equilibria of selfinteracting scalar fields, Phys. Rev. Lett. 57 (1986) 2485 [INSPIRE].
A.S. Sakharov and M.Y. Khlopov, The nonhomogeneity problem for the primordial axion field, Phys. Atom. Nucl. 57 (1994) 485 [Yad. Fiz. 57 (1994) 514] [INSPIRE].
E. Seidel and W.-M. Suen, Dynamical evolution of boson stars. 1. Perturbing the ground state, Phys. Rev. D 42 (1990) 384 [INSPIRE].
R. Friedberg, T.D. Lee and Y. Pang, Scalar soliton stars and black holes, Phys. Rev. D 35 (1987) 3658 [INSPIRE].
E. Seidel and W.M. Suen, Oscillating soliton stars, Phys. Rev. Lett. 66 (1991) 1659 [INSPIRE].
A.R. Liddle and M.S. Madsen, The structure and formation of boson stars, Int. J. Mod. Phys. D 1 (1992) 101 [INSPIRE].
T.D. Lee and Y. Pang, Nontopological solitons, Phys. Rept. 221 (1992) 251 [INSPIRE].
E.W. Mielke and F.E. Schunck, Boson stars: alternatives to primordial black holes?, Nucl. Phys. B 564 (2000) 185 [gr-qc/0001061] [INSPIRE].
J. Barranco and A. Bernal, Self-gravitating system made of axions, Phys. Rev. D 83 (2011) 043525 [arXiv:1001.1769] [INSPIRE].
J. Barranco and A. Bernal, Towards a realistic axion star, arXiv:0808.0081 [INSPIRE].
J. Barranco, A.C. Monteverde and D. Delepine, Can the dark matter halo be a collisionless ensemble of axion stars?, Phys. Rev. D 87 (2013) 103011 [arXiv:1212.2254] [INSPIRE].
J. Barranco, A.C. Monteverde and D. Delepine, Can the dark matter halo be a collisionless ensemble of axion stars?, Phys. Rev. D 87 (2013) 103011 [arXiv:1212.2254] [INSPIRE].
D.J. Gross, R.D. Pisarski and L.G. Yaffe, QCD and instantons at finite temperature, Rev. Mod. Phys. 53 (1981) 43 [INSPIRE].
M.S. Turner, Cosmic and local mass density of invisible axions, Phys. Rev. D 33 (1986) 889 [INSPIRE].
K. Freese, J.A. Frieman and A.V. Olinto, Natural inflation with pseudo-Nambu-Goldstone bosons, Phys. Rev. Lett. 65 (1990) 3233 [INSPIRE].
P. Sikivie, Axion cosmology, Lect. Notes Phys. 741 (2008) 19 [astro-ph/0610440] [INSPIRE].
Particle Data Group collaboration, C. Amsler et al., Review of particle physics, Phys. Lett. B 667 (2008) 1 [INSPIRE].
I.I. Tkachev, On the possibility of Bose star formation, Phys. Lett. B 261 (1991) 289 [INSPIRE].
J. Preskill, M.B. Wise and F. Wilczek, Cosmology of the invisible axion, Phys. Lett. B 120 (1983) 127 [INSPIRE].
L.F. Abbott and P. Sikivie, A cosmological bound on the invisible axion, Phys. Lett. B 120 (1983) 133 [INSPIRE].
M. Dine and W. Fischler, The not so harmless axion, Phys. Lett. B 120 (1983) 137 [INSPIRE].
G.V. Donogatski, Estimated upper bound of different hypothetical electron-proton interactions, based on the energy balance of the sun, Sov. J. Nucl. Phys. 8 (1969) 442.
D.A. Dicus, E.W. Kolb, V.L. Teplitz and R.V. Wagoner, Astrophysical bounds on the masses of axions and Higgs particles, Phys. Rev. D 18 (1978) 1829 [INSPIRE].
M. Fukugita, S. Watamura and M. Yoshimura, Light pseudoscalar particle and stellar energy loss, Phys. Rev. Lett. 48 (1982) 1522 [INSPIRE].
A. Barnacka, J.F. Glicenstein and R. Moderski, New constraints on primordial black holes abundance from femtolensing of gamma-ray bursts, Phys. Rev. D 86 (2012) 043001 [arXiv:1204.2056] [INSPIRE].
A. Iwazaki, Axionic boson stars in magnetized conducting media, Phys. Rev. D 60 (1999) 025001 [hep-ph/9901396] [INSPIRE].
D.R. Lorimer, M. Bailes, M.A. McLaughlin, D.J. Narkevic and F. Crawford, A bright millisecond radio burst of extragalactic origin, Science 318 (2007) 777 [arXiv:0709.4301] [INSPIRE].
E.F. Keane et al., Further searches for RRATs in the Parkes multi-beam pulsar survey, Mon. Not. Roy. Astron. Soc. 401 (2010) 1057 [arXiv:0909.1924] [INSPIRE].
D. Thornton et al., A population of fast radio bursts at cosmological distances, Science 341 (2013) 53 [arXiv:1307.1628] [INSPIRE].
L.G. Spitler et al., Fast radio burst discovered in the Arecibo pulsar ALFA survey, Astrophys. J. 790 (2014) 101 [arXiv:1404.2934] [INSPIRE].
A. Iwazaki, Axion stars and fast radio bursts, Phys. Rev. D 91 (2015) 023008 [arXiv:1410.4323] [INSPIRE].
A. Iwazaki, Fast radio bursts from axion stars, arXiv:1412.7825 [INSPIRE].
I.I. Tkachev, Fast radio bursts and axion miniclusters, arXiv:1411.3900 [INSPIRE].
T. Totani, Cosmological fast radio bursts from binary neutron star mergers, Pub. Astron. Soc. Jpn. 65 (2013) L12 [arXiv:1307.4985] [INSPIRE].
A. Loeb, Y. Shvartzvald and D. Maoz, Fast radio bursts may originate from nearby flaring stars, Mon. Not. Roy. Astron. Soc. 439 (2014) 46 [arXiv:1310.2419] [INSPIRE].
K.W. Bannister and G.J. Madsen, A galactic origin for the fast radio burst F RB010621, Mon. Not. Roy. Astron. Soc. 440 (2014) 353 [arXiv:1402.0268] [INSPIRE].
Open Access
This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
Author information
Authors and Affiliations
Corresponding author
Additional information
ArXiv ePrint: 1412.3430
An erratum to this article is available at http://dx.doi.org/10.1007/JHEP11(2016)134.
Rights and permissions
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0), which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
About this article
Cite this article
Eby, J., Suranyi, P., Vaz, C. et al. Axion stars in the infrared limit. J. High Energ. Phys. 2015, 80 (2015). https://doi.org/10.1007/JHEP03(2015)080
Received:
Revised:
Accepted:
Published:
DOI: https://doi.org/10.1007/JHEP03(2015)080