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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260919T160018Z
LAST-MODIFIED:20190124T213641Z
DTSTART:20190131T203000Z
DTEND:20190131T213000Z
UID:event2098@bu.edu
URL:http://physics.bu.edu/internal/events/show/2098
SUMMARY:How To Resolve The Hubble Tension
DESCRIPTION:Featuring Vivian Poulin\, Johns Hopkins\n\nPart of the HET Semi
	nar Series.\n\nLocal measurements of the Hubble parameter from type 1a supe
	rnovae disagree at almost 4sigma with the value inferred from a ΛCDM fit t
	o the cosmic microwave background (CMB)\, with local measurements suggestin
	g a higher value.  This discrepancy is not easily explained by any obvious 
	systematic effect in either measurement\, and so increasing attention is gi
	ven to the possibility that this "Hubble tension" may be indicating new phy
	sics beyond ΛCDM. In this talk\, I would like to review promising solution
	s to this tension. I will first argue that this discrepancy should be inter
	preted as a tension between our understanding of the early and late univers
	e cosmology\, rather than a tension between two datasets. Secondly\, I will
	 show that this observation might indicate that our Universe has undergone 
	anomalous expansion due to the presence of an early dark energy (EDE) at re
	dshift z ~ 5000. I will give two examples of a physical model that lead to 
	the desired dynamics. Moreover\, I will explain why this solution is favore
	d over modifications of the dark energy dynamics (the so-called "phantom" d
	ark energy) as well as favored over the presence of an additional relativis
	tic degree of freedom.
LOCATION:PRB 595\, 3 Cummington Mall\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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