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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-1383
DTSTART:20090507T210000Z
DURATION:PT1H0M0S
DTSTAMP:20260422T214702Z
LAST-MODIFIED:20090504T133204Z
LOCATION:5310 Chamberlin
SUMMARY:High Precision Cosmology with Baryon Acoustic Oscillations\, N
 PAC (Nuclear/Particle/Astro/Cosmo) Forum\, Hee-Jong Seo\, Fermilab and
  U. Arizona
DESCRIPTION:Baryon acoustic oscillations (BAO) in large galaxy surveys
  can provide an excellent standard ruler test to measure the cosmologi
 cal distance scale\, such as the angular diameter distance and the Hub
 ble parameter\, and therefore dark energy properties. This requires th
 at we understand all of the physical effects that could alter the acou
 stic feature during the nonlinear evolution of structure. There are tw
 o important aspects of the nonlinear effects on BAO. First\, the BAO s
 ignature is gradually reduced with time and in scale due to nonlinear 
 growth of density fields\, redshift distortions\, and galaxy bias. Sec
 ond\, the various nonlinear effects may alter the observed BAO scale a
 t low redshift\, relative to the linear acoustic scale derived from th
 e CMB\, which would result in biased estimation of dark energy paramet
 ers. In this talk\, I will present effects of such nonlinearities on B
 AO from N-body results: nonlinear growth and redshift distortions degr
 ade the contrast of BAO while shifting BAO less than ~0.5% at z=0.3. I
  will show that most of these nonlinear effects can be reversed by a s
 imple reconstruction scheme.I will also discuss the effect of galaxy b
 ias on BAO.
URL:https://www.physics.wisc.edu/events/?id=1383
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