TY - JOUR
T1 - Supersonic relative velocity effect on the baryonic acoustic oscillation measurements
AU - Yoo, Jaiyul
AU - Dalal, Neal
AU - Seljak, Uroš
PY - 2011/7
Y1 - 2011/7
N2 - We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum analysis to constrain dark energy models with high precision.
AB - We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum analysis to constrain dark energy models with high precision.
KW - baryon acoustic oscillations
KW - galaxy clustering
KW - power spectrum
UR - http://www.scopus.com/inward/record.url?scp=79961241142&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79961241142&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2011/07/018
DO - 10.1088/1475-7516/2011/07/018
M3 - Article
AN - SCOPUS:79961241142
SN - 1475-7516
VL - 2011
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 7
M1 - 018
ER -