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Title: Astrophysical effects of scalar dark matter miniclusters

Abstract

We model the formation, evolution and astrophysical effects of dark compact Scalar Miniclusters ('ScaMs'). These objects arise when a scalar field, with an axion-like or Higgs-like potential, undergoes a second-order phase transition below the QCD scale. Such a scalar field may couple too weakly to the standard model to be detectable directly through particle interactions, but may still be detectable by gravitational effects, such as lensing and baryon accretion by large, gravitationally bound miniclusters. The masses of these objects are shown to be constrained by the Ly{alpha} power spectrum to be less than {approx}10{sup 4}M{sub {center_dot}}, but they may be as light as classical axion miniclusters, of the order of 10{sup -12}M{sub {center_dot}}. We simulate the formation and nonlinear gravitational collapse of these objects around matter-radiation equality using an N-body code, estimate their gravitational lensing properties, and assess the feasibility of studying them using current and future lensing experiments. Future MACHO-type variability surveys of many background sources can reveal either high-amplification, strong-lensing events, or measure density profiles directly via weak-lensing variability, depending on ScaM parameters and survey depth. However, ScaMs, due to their low internal densities, are unlikely to be responsible for apparent MACHO events already detected in the Galacticmore » halo. As a result, in the entire window between 10{sup -7}M{sub {center_dot}} and 10{sup 2}M{sub {center_dot}} covered by the galactic scale lensing experiments, ScaMs may in fact compose all the dark matter. A simple estimate is made of parameters that would give rise to early structure formation; in principle, early stellar collapse could be triggered by ScaMs as early as recombination, and significantly affect cosmic reionization.« less

Authors:
; ;  [1]
  1. Physics and Astronomy Departments, University of Washington, Seattle, Washington 98195 (United States)
Publication Date:
OSTI Identifier:
21011054
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevD.75.043511; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; AXIONS; BARYONS; COSMOLOGY; GRAVITATIONAL COLLAPSE; HIGGS BOSONS; HIGGS MODEL; NONLINEAR PROBLEMS; NONLUMINOUS MATTER; PARTICLE INTERACTIONS; PHASE TRANSFORMATIONS; POTENTIALS; QUANTUM CHROMODYNAMICS; SCALAR FIELDS; STANDARD MODEL

Citation Formats

Zurek, Kathryn M., Hogan, Craig J., and Quinn, Thomas R.. Astrophysical effects of scalar dark matter miniclusters. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.043511.
Zurek, Kathryn M., Hogan, Craig J., & Quinn, Thomas R.. Astrophysical effects of scalar dark matter miniclusters. United States. doi:10.1103/PHYSREVD.75.043511.
Zurek, Kathryn M., Hogan, Craig J., and Quinn, Thomas R.. Thu . "Astrophysical effects of scalar dark matter miniclusters". United States. doi:10.1103/PHYSREVD.75.043511.
@article{osti_21011054,
title = {Astrophysical effects of scalar dark matter miniclusters},
author = {Zurek, Kathryn M. and Hogan, Craig J. and Quinn, Thomas R.},
abstractNote = {We model the formation, evolution and astrophysical effects of dark compact Scalar Miniclusters ('ScaMs'). These objects arise when a scalar field, with an axion-like or Higgs-like potential, undergoes a second-order phase transition below the QCD scale. Such a scalar field may couple too weakly to the standard model to be detectable directly through particle interactions, but may still be detectable by gravitational effects, such as lensing and baryon accretion by large, gravitationally bound miniclusters. The masses of these objects are shown to be constrained by the Ly{alpha} power spectrum to be less than {approx}10{sup 4}M{sub {center_dot}}, but they may be as light as classical axion miniclusters, of the order of 10{sup -12}M{sub {center_dot}}. We simulate the formation and nonlinear gravitational collapse of these objects around matter-radiation equality using an N-body code, estimate their gravitational lensing properties, and assess the feasibility of studying them using current and future lensing experiments. Future MACHO-type variability surveys of many background sources can reveal either high-amplification, strong-lensing events, or measure density profiles directly via weak-lensing variability, depending on ScaM parameters and survey depth. However, ScaMs, due to their low internal densities, are unlikely to be responsible for apparent MACHO events already detected in the Galactic halo. As a result, in the entire window between 10{sup -7}M{sub {center_dot}} and 10{sup 2}M{sub {center_dot}} covered by the galactic scale lensing experiments, ScaMs may in fact compose all the dark matter. A simple estimate is made of parameters that would give rise to early structure formation; in principle, early stellar collapse could be triggered by ScaMs as early as recombination, and significantly affect cosmic reionization.},
doi = {10.1103/PHYSREVD.75.043511},
journal = {Physical Review. D, Particles Fields},
number = 4,
volume = 75,
place = {United States},
year = {Thu Feb 15 00:00:00 EST 2007},
month = {Thu Feb 15 00:00:00 EST 2007}
}
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