Title
Constraints on superstrings, inflation, and extra dimensions from the CMB and big bang nucleosynthesis
Abstract
The energy scale of superstrings was obtainable iduring the early moments of chaotic
inflation out of the string theory landscape. This talk explores the possibility that a
specific superstring excitation may have made itself known via its coupling to the field of
inflation. This may have left an imprint of “dips” in the power spectrum of temperature
fluctuations in the cosmic microwave background. The identification of this particle
as a superstring is possible because there may be evidence for different oscillator states
of the same superstring that appear on different scales on the sky. It will be shown
that from this imprint one can deduce the mass, number of oscillations, and coupling
constant for the superstring. Although the evidence is marginal, this may constitute the
first observation of a superstring in Nature. At the same time, the existence of extra
dimensions during inflation impacts the tensor to scalar ratio and the running spectral
index. We summarize how the constraints on inflation shift when embedded in higher
dimensions. Finally, higher dimensions also impact the cosmic expansion through the
projection of curvature from the higher dimension in the “dark radiation” term. We
summarize current constraints from BBN and the CMB on this brane-world dark radiation
term.
Suggested Citation
Mathews, Grant.
(2017).
Constraints on superstrings, inflation, and extra dimensions from the CMB and big bang nucleosynthesis.
Retrieved from the University of Minnesota Digital Conservancy,
https://hdl.handle.net/11299/188212.