UV/IR mode mixing and the CMB

Jun, 2009
11 pages
Published in:
  • Phys.Rev.D 80 (2009) 083010
e-Print:
Report number:
  • HU-EP-09-18

Citations per year

200920112013201520172103
Abstract: (arXiv)
It is well understood that spatial non-commutativity, if indeed realized in nature, is a phenomenon whose effects are not just felt at energy scales comparable to the non-commutativity scale. Loop effects can transmit signatures of any underlying non-commutativity to macroscopic scales (a manifestation of a phenomenon that has come to be known as UV/IR mode mixing) and offer a potential window to constrain the amount of non-commutativity present in nature, if present at all. Field theories defined on non-commutative spaces (realized in string theory when D-branes are coupled to backgrounds of non-trivial RR background flux), can exhibit strong UV/IR mode mixing, manifesting in a non-local one loop effective action. In the context of inflation in the presence of any background non-commutativity, we demonstrate how this UV/IR mixing at the loop level can allow us to place severe constraints on the scale of non-commutativity if we presume inflation is responsible for large scale structure. We demonstrate that any amount of non-commutativity greatly suppresses the CMB power at all observable scales, independent of the scale of inflation, and independent of whether or not the non-commutativity tensor redshifts during inflation, therefore nullifying a very salient and successful prediction of inflation.
Note:
  • 11 pages, 2 figures, RevTeX4
  • 98.80.Cq
  • 11.25.Wx
  • scale: inflation
  • space: noncommutative
  • D-brane
  • infrared
  • flux: background
  • perturbation theory: higher-order
  • phi**n model
  • power spectrum