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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Physics-TWaP
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-2849
DTSTART:20121113T220000Z
DURATION:PT1H0M0S
DTSTAMP:20180122T080350Z
LAST-MODIFIED:20121112T155855Z
LOCATION:5280 Chamberlin
SUMMARY:Cosmological Perturbations: Isocurvature\, Vorticity and Magnetic Fields\, Theory Seminar (High Energy/Cosmology)\, Adam Christopherson\, University of Nottingham
DESCRIPTION:In this talk I will discuss some recent\, complementary work that I have undertaken using cosmological perturbation theory\, a powerful technique for modeling inhomogeneities in the universe. After a brief review of the basics\, I introduce isocurvature\, or non-adiabatic pressure perturbations\, and calculate their spectrum in the settings of standard\, concordance cosmology\, and inflationary models involving two scalar fields. I then extend the discussion beyond linear perturbations\, and show that vorticity can be sourced at second order with only scalar perturbations\, the source term being quadratic in the gradients of first order energy density and non-adiabatic pressure perturbations. I present a first estimate of this vorticity's power spectrum\, and highlight some potential observational consequences. One of these is the possible sourcing of sizeable magnetic fields\, and I briefly sketch some current work on including magnetic fields in perturbation theory in a consistent way. I close with some ideas for future work.
URL:http://www.physics.wisc.edu/twap/view.php?id=2849
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