B polarization of the cosmic microwave background as a tracer of strings
- Department of Physics, Princeton University, Princeton New Jersey 08544 (United States)
- Faculty of Mathematics and Physics, University of Ljubljana (Slovenia)
String models can produce successful inflationary scenarios in the context of brane collisions, and in many of these models cosmic strings may also be produced. In scenarios such as Kachru-Kallosh-Linde-Maldacena-McAllister-Trivedi (KKLMMT) scenario the string contribution is naturally predicted to be well below the inflationary signal for cosmic microwave background (CMB) temperature anisotropies, in agreement with the existing limits. We find that for B type polarization of CMB the situation is reversed and the dominant signal comes from vector modes generated by cosmic strings, which exceeds the gravity wave signal from both inflation and strings. The signal can be detected for a broad range of parameter space; future polarization experiments may be able to detect the string signal down to the string tension G{mu}=10{sup -9}, although foregrounds and lensing are likely to worsen these limits. We argue that the optimal scale to search for the string signature is at l{approx}1000, but in models with high optical depth the signal from reionization peak at large scales is also significant. The shape of the power spectrum allows one to distinguish the string signature from the gravity waves from inflation, but only with a sufficiently high angular resolution experiment.
- OSTI ID:
- 20871197
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 74, Issue 6; Other Information: DOI: 10.1103/PhysRevD.74.063523; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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