Dilute and dense axion stars
Abstract
Axion stars are hypothetical objects formed of axions, obtained as localized and coherently oscillating solutions to their classical equation of motion. Depending on the value of the field amplitude at the core |$$\theta_0$$|≡ |$$\theta$$ (r=0), the equilibrium of the system arises from the balance of the kinetic pressure and either self-gravity or axion self-interactions. Starting from a general relativistic framework, we obtain the set of equations describing the configuration of the axion star, which we solve as a function of |$$\theta_0$$|. For small |$$\theta_0$$|≲1, we reproduce results previously obtained in the literature, and we provide arguments for the stability of such configurations in terms of first principles. We compare qualitative analytical results with a numerical calculation. For large amplitudes |$$\theta_0$$|≳1, the axion field probes the full non-harmonic QCD chiral potential and the axion star enters the $dense$ branch. Our numerical solutions show that in this latter regime the axions are relativistic, and that one should not use a single frequency approximation, as previously applied in the literature. We employ a multi-harmonic expansion to solve the relativistic equation for the axion field in the star, and demonstrate that higher modes cannot be neglected in the dense regime. We interpret the solutions in the dense regime as pseudo-breathers, and show that the life-time of such configurations is much smaller than any cosmological time scale.
- Authors:
- Publication Date:
- Research Org.:
- Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Univ. of Michigan, Ann Arbor, MI (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), High Energy Physics (HEP); European Research Council (ERC); Swedish Research Council (SRC)
- OSTI Identifier:
- 1437800
- Alternate Identifier(s):
- OSTI ID: 1499285; OSTI ID: 1646990
- Grant/Contract Number:
- SC0012567; SC007859; 638-2013-8993; 335-2014-7424; FPA2015-65745-P; SFB-1258; 742104; SC0007859
- Resource Type:
- Published Article
- Journal Name:
- Physics Letters B
- Additional Journal Information:
- Journal Name: Physics Letters B Journal Volume: 777 Journal Issue: C; Journal ID: ISSN 0370-2693
- Publisher:
- Elsevier
- Country of Publication:
- Netherlands
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 79 ASTRONOMY AND ASTROPHYSICS
Citation Formats
Visinelli, Luca, Baum, Sebastian, Redondo, Javier, Freese, Katherine, and Wilczek, Frank. Dilute and dense axion stars. Netherlands: N. p., 2018.
Web. doi:10.1016/j.physletb.2017.12.010.
Visinelli, Luca, Baum, Sebastian, Redondo, Javier, Freese, Katherine, & Wilczek, Frank. Dilute and dense axion stars. Netherlands. https://doi.org/10.1016/j.physletb.2017.12.010
Visinelli, Luca, Baum, Sebastian, Redondo, Javier, Freese, Katherine, and Wilczek, Frank. Thu .
"Dilute and dense axion stars". Netherlands. https://doi.org/10.1016/j.physletb.2017.12.010.
@article{osti_1437800,
title = {Dilute and dense axion stars},
author = {Visinelli, Luca and Baum, Sebastian and Redondo, Javier and Freese, Katherine and Wilczek, Frank},
abstractNote = {Axion stars are hypothetical objects formed of axions, obtained as localized and coherently oscillating solutions to their classical equation of motion. Depending on the value of the field amplitude at the core |$\theta_0$|≡ |$\theta$ (r=0), the equilibrium of the system arises from the balance of the kinetic pressure and either self-gravity or axion self-interactions. Starting from a general relativistic framework, we obtain the set of equations describing the configuration of the axion star, which we solve as a function of |$\theta_0$|. For small |$\theta_0$|≲1, we reproduce results previously obtained in the literature, and we provide arguments for the stability of such configurations in terms of first principles. We compare qualitative analytical results with a numerical calculation. For large amplitudes |$\theta_0$|≳1, the axion field probes the full non-harmonic QCD chiral potential and the axion star enters the $dense$ branch. Our numerical solutions show that in this latter regime the axions are relativistic, and that one should not use a single frequency approximation, as previously applied in the literature. We employ a multi-harmonic expansion to solve the relativistic equation for the axion field in the star, and demonstrate that higher modes cannot be neglected in the dense regime. We interpret the solutions in the dense regime as pseudo-breathers, and show that the life-time of such configurations is much smaller than any cosmological time scale.},
doi = {10.1016/j.physletb.2017.12.010},
journal = {Physics Letters B},
number = C,
volume = 777,
place = {Netherlands},
year = {2018},
month = {2}
}
https://doi.org/10.1016/j.physletb.2017.12.010
Web of Science
Figures / Tables:

Works referenced in this record:
Systems of Self-Gravitating Particles in General Relativity and the Concept of an Equation of State
journal, November 1969
- Ruffini, Remo; Bonazzola, Silvano
- Physical Review, Vol. 187, Issue 5
The not-so-harmless axion
journal, January 1983
- Dine, Michael; Fischler, Willy
- Physics Letters B, Vol. 120, Issue 1-3
Cosmology of the invisible axion
journal, January 1983
- Preskill, John; Wise, Mark B.; Wilczek, Frank
- Physics Letters B, Vol. 120, Issue 1-3
Can confinement ensure natural CP invariance of strong interactions?
journal, April 1980
- Shifman, M. A.; Vainshtein, A. I.; Zakharov, V. I.
- Nuclear Physics B, Vol. 166, Issue 3
Gauge-field non-topological solitons in three space-dimensions (II)
journal, November 1976
- Friedberg, R.; Lee, T. D.; Sirlin, A.
- Nuclear Physics B, Vol. 115, Issue 1
Nonlinear axion dynamics and the formation of cosmological pseudosolitons
journal, May 1994
- Kolb, Edward W.; Tkachev, Igor I.
- Physical Review D, Vol. 49, Issue 10
Problem of Strong and Invariance in the Presence of Instantons
journal, January 1978
- Wilczek, F.
- Physical Review Letters, Vol. 40, Issue 5
Method for Solving the Sine-Gordon Equation
journal, June 1973
- Ablowitz, M. J.; Kaup, D. J.; Newell, A. C.
- Physical Review Letters, Vol. 30, Issue 25
A simple solution to the strong CP problem with a harmless axion
journal, August 1981
- Dine, Michael; Fischler, Willy; Srednicki, Mark
- Physics Letters B, Vol. 104, Issue 3
Emission of photons and relativistic axions from axion stars
journal, August 2017
- Braaten, Eric; Mohapatra, Abhishek; Zhang, Hong
- Physical Review D, Vol. 96, Issue 3
Do dark matter axions form a condensate with long-range correlation?
journal, November 2015
- Guth, Alan H.; Hertzberg, Mark P.; Prescod-Weinstein, C.
- Physical Review D, Vol. 92, Issue 10
Axion cosmology and the energy scale of inflation
journal, October 2008
- Hertzberg, Mark P.; Tegmark, Max; Wilczek, Frank
- Physical Review D, Vol. 78, Issue 8
Oscillating soliton stars
journal, April 1991
- Seidel, Edward; Suen, Wai-Mo
- Physical Review Letters, Vol. 66, Issue 13
Radiation and relaxation of oscillons
journal, April 2012
- Salmi, Petja; Hindmarsh, Mark
- Physical Review D, Vol. 85, Issue 8
IV. Examples of four-dimensional soliton solutions and abnormal nuclear states
journal, February 1976
- Lee, T. D.
- Physics Reports, Vol. 23, Issue 3
Constraints imposed by conservation in the presence of pseudoparticles
journal, September 1977
- Peccei, R. D.; Quinn, Helen R.
- Physical Review D, Vol. 16, Issue 6
Chiral dynamics in the large N limit
journal, January 1980
- Di Vecchia, P.; Veneziano, G.
- Nuclear Physics B, Vol. 171
Oscillons: Resonant configurations during bubble collapse
journal, August 1995
- Copeland, E. J.; Gleiser, M.; Müller, H. -R.
- Physical Review D, Vol. 52, Issue 4
Conservation in the Presence of Pseudoparticles
journal, June 1977
- Peccei, R. D.; Quinn, Helen R.
- Physical Review Letters, Vol. 38, Issue 25
The lifetime of axion stars
journal, May 2016
- Eby, Joshua; Suranyi, Peter; Wijewardhana, L. C. R.
- Modern Physics Letters A, Vol. 31, Issue 15
Relativistic Axions from Collapsing Bose Stars
journal, January 2017
- Levkov, D. G.; Panin, A. G.; Tkachev, I. I.
- Physical Review Letters, Vol. 118, Issue 1
Weak-Interaction Singlet and Strong Invariance
journal, July 1979
- Kim, Jihn E.
- Physical Review Letters, Vol. 43, Issue 2
Dynamics of classical solitons (in non-integrable systems)
journal, January 1978
- Makhankov, V. G.
- Physics Reports, Vol. 35, Issue 1
Rotating drops of axion dark matter
journal, June 2016
- Davidson, Sacha; Schwetz, Thomas
- Physical Review D, Vol. 93, Issue 12
Dense Axion Stars
journal, September 2016
- Braaten, Eric; Mohapatra, Abhishek; Zhang, Hong
- Physical Review Letters, Vol. 117, Issue 12
Dark matter axions revisited
journal, August 2009
- Visinelli, Luca; Gondolo, Paolo
- Physical Review D, Vol. 80, Issue 3
Particle spectrum in model field theories from semiclassical functional integral techniques
journal, June 1975
- Dashen, Roger F.; Hasslacher, Brosl; Neveu, André
- Physical Review D, Vol. 11, Issue 12
Gauge-field non-topological solitons in three space-dimensions (I)
journal, November 1976
- Freidberg, R.; Lee, T. D.; Sirlin, A.
- Nuclear Physics B, Vol. 115, Issue 1
Metastable stationary solutions of the radial d -dimensional sine-Gordon model
journal, July 1998
- Piette, B.; Zakrzewski, W. J.
- Nonlinearity, Vol. 11, Issue 4
Comments on Nonlinear Wave Equations as Models for Elementary Particles
journal, September 1964
- Derrick, G. H.
- Journal of Mathematical Physics, Vol. 5, Issue 9
Searching for axions and ALPs from string theory
journal, March 2014
- Ringwald, Andreas
- Journal of Physics: Conference Series, Vol. 485
Long-lived localized field configurations in small lattices: Application to oscillons
journal, July 2000
- Gleiser, M.; Sornborger, A.
- Physical Review E, Vol. 62, Issue 1
Oscillatons revisited
journal, April 2002
- Ure$ntilde$a-L$oacute$pez, L. Arturo
- Classical and Quantum Gravity, Vol. 19, Issue 10
Tentative relativistic model for neutral Yukawa systems
journal, July 1975
- Teixeira, A. F. da F.; Wolk, Idel; Som, M. M.
- Physical Review D, Vol. 12, Issue 2
Stable States of a Scalar Particle in Its Own Gravational Field
journal, April 1968
- Feinblum, David A.; McKinley, William A.
- Physical Review, Vol. 168, Issue 5
Axion miniclusters and Bose stars
journal, November 1993
- Kolb, Edward W.; Tkachev, Igor I.
- Physical Review Letters, Vol. 71, Issue 19
Calculation of the axion mass based on high-temperature lattice quantum chromodynamics
journal, November 2016
- Borsanyi, S.; Fodor, Z.; Guenther, J.
- Nature, Vol. 539, Issue 7627
On the possibility of Bose-star formation
journal, May 1991
- Tkachev, I. I.
- Physics Letters B, Vol. 261, Issue 3
General theory of oscillon dynamics
journal, December 2009
- Gleiser, Marcelo; Sicilia, David
- Physical Review D, Vol. 80, Issue 12
On radial sine-Gordon breathers
journal, July 2000
- Alfimov, G. L.; Evans, W. A. B.; Vázquez, L.
- Nonlinearity, Vol. 13, Issue 5
Boson Stars: Gravitational Equilibria of Self-Interacting Scalar Fields
journal, November 1986
- Colpi, Monica; Shapiro, Stuart L.; Wasserman, Ira
- Physical Review Letters, Vol. 57, Issue 20
Complex Scalar Field in General Relativity
journal, January 1963
- Das, A.
- Journal of Mathematical Physics, Vol. 4, Issue 1
Charged Particlelike Solutions to Nonlinear Complex Scalar Field Theories
journal, July 1968
- Rosen, Gerald
- Journal of Mathematical Physics, Vol. 9, Issue 7
A cosmological bound on the invisible axion
journal, January 1983
- Abbott, L. F.; Sikivie, P.
- Physics Letters B, Vol. 120, Issue 1-3
Oscillons and quasibreathers in the Klein-Gordon model
journal, December 2006
- Fodor, Gyula; Forgács, Péter; Grandclément, Philippe
- Physical Review D, Vol. 74, Issue 12
The topological susceptibility in finite temperature QCD and axion cosmology
journal, November 2016
- Petreczky, Peter; Schadler, Hans-Peter; Sharma, Sayantan
- Physics Letters B, Vol. 762
Using the Schroedinger Equation to Simulate Collisionless Matter
journal, October 1993
- Widrow, Lawrence M.; Kaiser, Nick
- The Astrophysical Journal, Vol. 416
Axion dark matter, solitons and the cusp–core problem
journal, June 2015
- Marsh, David J. E.; Pop, Ana-Roxana
- Monthly Notices of the Royal Astronomical Society, Vol. 451, Issue 3
Cylindrical Pulsons in Nonlinear Relativistic Wave Equations
journal, May 1984
- Geicke, J.
- Physica Scripta, Vol. 29, Issue 5
Quintessence and scalar dark matter in the Universe
journal, June 2000
- Matos, Tonatiuh; Ureña-López, L. Arturo
- Classical and Quantum Gravity, Vol. 17, Issue 13
Analytical Characterization of Oscillon Energy and Lifetime
journal, July 2008
- Gleiser, Marcelo; Sicilia, David
- Physical Review Letters, Vol. 101, Issue 1
Works referencing / citing this record:
Expansion in higher harmonics of boson stars using a generalized Ruffini-Bonazzola approach. Part 1. Bound states
journal, April 2018
- Eby, Joshua; Suranyi, Peter; Wijewardhana, L. C. R.
- Journal of Cosmology and Astroparticle Physics, Vol. 2018, Issue 04
Stability of condensed fuzzy dark matter halos
journal, October 2018
- Eby, Joshua; Leembruggen, Madelyn; Suranyi, Peter
- Journal of Cosmology and Astroparticle Physics, Vol. 2018, Issue 10
Boson star from repulsive light scalars and gravitational waves
journal, April 2019
- Croon, Djuna; Fan, JiJi; Sun, Chen
- Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 04
Axion dark matter from Higgs inflation with an intermediate H *
journal, August 2019
- Tenkanen, Tommi; Visinelli, Luca
- Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 08
Light majoron cold dark matter from topological defects and the formation of boson stars
journal, September 2019
- Reig, Mario; Valle, José W. F.; Yamada, Masaki
- Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 09
Axion boson stars
journal, September 2019
- Guerra, Davide; Macedo, Caio F. B.; Pani, Paolo
- Journal of Cosmology and Astroparticle Physics, Vol. 2019, Issue 09
Oscillons and dark matter
journal, February 2020
- Ollé, Jan; Pujolàs, Oriol; Rompineve, Fabrizio
- Journal of Cosmology and Astroparticle Physics, Vol. 2020, Issue 02
Axion core–halo mass and the black hole–halo mass relation: constraints on a few parsec scales
journal, July 2019
- Desjacques, Vincent; Nusser, Adi
- Monthly Notices of the Royal Astronomical Society, Vol. 488, Issue 4
Effective field theory for black holes with induced scalar charges
journal, July 2019
- Wong, Leong Khim; Davis, Anne-Christine; Gregory, Ruth
- Physical Review D, Vol. 100, Issue 2
Formation, gravitational clustering, and interactions of nonrelativistic solitons in an expanding universe
journal, September 2019
- Amin, Mustafa A.; Mocz, Philip
- Physical Review D, Vol. 100, Issue 6
Formation and mass growth of axion stars in axion miniclusters
journal, September 2019
- Eggemeier, Benedikt; Niemeyer, Jens C.
- Physical Review D, Vol. 100, Issue 6
Derivation of the core mass-halo mass relation of fermionic and bosonic dark matter halos from an effective thermodynamical model
journal, December 2019
- Chavanis, Pierre-Henri
- Physical Review D, Vol. 100, Issue 12
Axion miniclusters in modified cosmological histories
journal, January 2020
- Visinelli, Luca; Redondo, Javier
- Physical Review D, Vol. 101, Issue 2
Relativistic corrections to nonrelativistic effective field theories
journal, July 2018
- Namjoo, Mohammad Hossein; Guth, Alan H.; Kaiser, David I.
- Physical Review D, Vol. 98, Issue 1
Can light dark matter solve the core-cusp problem?
journal, July 2018
- Deng, Heling; Hertzberg, Mark P.; Namjoo, Mohammad Hossein
- Physical Review D, Vol. 98, Issue 2
Axion cosmology with early matter domination
journal, September 2018
- Nelson, Ann E.; Xiao, Huangyu
- Physical Review D, Vol. 98, Issue 6
Jeans-type instability of a complex self-interacting scalar field in general relativity
journal, October 2018
- Suárez, Abril; Chavanis, Pierre-Henri
- Physical Review D, Vol. 98, Issue 8
Cosmological window onto the string axiverse and the supersymmetry breaking scale
journal, March 2019
- Visinelli, Luca; Vagnozzi, Sunny
- Physical Review D, Vol. 99, Issue 6
Classical nonrelativistic effective field theory and the role of gravitational interactions
journal, June 2019
- Eby, Joshua; Mukaida, Kyohei; Takimoto, Masahiro
- Physical Review D, Vol. 99, Issue 12
Gravitational Bose-Einstein Condensation in the Kinetic Regime
journal, October 2018
- Levkov, D. G.; Panin, A. G.; Tkachev, I. I.
- Physical Review Letters, Vol. 121, Issue 15
Colloquium : The physics of axion stars
journal, October 2019
- Braaten, Eric; Zhang, Hong
- Reviews of Modern Physics, Vol. 91, Issue 4
Acoustic modes of pulsating axion stars: Nonradial oscillations
journal, July 2019
- Panotopoulos, Grigoris; Lopes, Ilídio
- International Journal of Modern Physics D, Vol. 28, Issue 09
Several Problems in Particle Physics and Cosmology Solved in One SMASH
text, January 2019
- Ballesteros, Guillermo; Redondo, Javier; Ringwald, Andreas
- Deutsches Elektronen-Synchrotron, DESY, Hamburg
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