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Title: Dense Axion Stars

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1325291
Grant/Contract Number:
SC0011726
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 117; Journal Issue: 12; Related Information: CHORUS Timestamp: 2016-09-16 18:10:33; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Braaten, Eric, Mohapatra, Abhishek, and Zhang, Hong. Dense Axion Stars. United States: N. p., 2016. Web. doi:10.1103/PhysRevLett.117.121801.
Braaten, Eric, Mohapatra, Abhishek, & Zhang, Hong. Dense Axion Stars. United States. doi:10.1103/PhysRevLett.117.121801.
Braaten, Eric, Mohapatra, Abhishek, and Zhang, Hong. 2016. "Dense Axion Stars". United States. doi:10.1103/PhysRevLett.117.121801.
@article{osti_1325291,
title = {Dense Axion Stars},
author = {Braaten, Eric and Mohapatra, Abhishek and Zhang, Hong},
abstractNote = {},
doi = {10.1103/PhysRevLett.117.121801},
journal = {Physical Review Letters},
number = 12,
volume = 117,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevLett.117.121801

Citation Metrics:
Cited by: 10works
Citation information provided by
Web of Science

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  • The energy-loss rate due to axion bremsstrahlung in dense stars such as white dwarfs or neutron stars is calculated by taking into account the phonon contributions in the crystalline lattice state accurately. It is found that the phonon contributions amount to 50-70 percent of the state lattice contributions near the melting temperature. Accurate analytic fitting formulas for the axion bremsstrahlung rate are given. 11 references.
  • Recently an effective Lagrangian for the interactions of photons, Nambu-Goldstone bosons and superfluid phonons in dense quark matter has been derived using anomaly matching arguments. In this paper we illuminate the nature of certain anomalous terms in this Lagrangian by an explicit microscopic calculation. We also generalize the corresponding construction to introduce the axion field. We derive an anomalous axion effective Lagrangian describing the interactions of axions with photons and superfluid phonons in the dense matter background. This effective Lagrangian, among other things, implies that an axion current will be induced in the presence of magnetic field. We speculate thatmore » this current may be responsible for the explanation of neutron star kicks.« less
  • Evolution of inhomogeneities in the axion field around the QCD epoch is studied numerically, including for the first time important nonlinear effects. It is found that perturbations on scales corresponding to causally disconnected regions at [ital T][similar to]1 GeV can lead to very dense axion clumps, with present density [rho][sub [ital a]][approx gt]10[sup [minus]8] g cm[sup [minus]3]. This is high enough for the collisional 2[ital a][r arrow]2[ital a] process to lead to Bose-Einstein relaxation in the gravitationally bound clumps of axions, forming Bose stars.
  • It is pointed out that the emission of axions from stellar plasmas and their reabsorption is stimulated by the thermal radiation field in processes with final-state photons. An expression for the bremsstrahlung emissivity of a stellar plasma is given for the nonrelativistic, degenerate regime. Some other aspects of a recent calculation by Pantziris and Kang of stellar axion emissivities are discussed.
  • The energy loss rate of a magnetized electron gas emitting axions a due to the process e{sup {minus}}{r_arrow}e{sup {minus}}+a is derived for arbitrary magnetic field strength B. Requiring that for a strongly magnetized neutron star the axion luminosity is smaller than the neutrino luminosity we obtain the bound g{sub ae}{approx_lt}10{sup {minus}10} for the axion electron coupling constant. This limit is considerably weaker than the bound derived earlier by Borisov and Grishina using the same method. Applying a similar argument to magnetic white dwarf stars results in the more stringent bound g{sub ae}{approx_lt}9{times}10{sup {minus}13}(T/10{sup 7}K){sup 5/4}(B/10{sup 10}G){sup {minus}2}, where T ismore » the internal temperature of the white dwarf. {copyright} {ital 1997} {ital The American Physical Society}« less