College of Science
Physics and Astronomy
This paper is an attempt to introduce the concept of gravitational waves, interpret the results of BICEP2 and Planck, analyze the methods employed by both missions, and evaluate the implications of the existence of inflationary gravitational waves (IGWs). BICEP2/Keck Array are experiments aimed at meas-uring the polarization of the cosmic microwave back-ground (CMB), as well as providing speculation re-garding the origin of B-Mode polarization of the CMB. In June 2014, BICEP2 reported the detection of such polarization but acknowledged uncertainty regarding its origin due to the possibility of gravita-tional lensing caused by cosmic dust. BICEP2’s de-tection used a CMB polarimeter specifically designed to observe the B-mode power spectrum around a multipole moment l ~ 80. In May 2015, the European Space Agency’s Planck mission published a mapping of the intensity and polarization of the sky at micro-wave frequencies in an attempt to address the prob-lem of cosmic dust. In a joint analysis of their data in 2015, BICEP2/Keck Array and Planck, by evaluating the tensor-to-scalar ratio r, concluded that confirma-tion of inflationary gravitational waves would require additional data. The detection of inflationary gravita-tional waves would have a profound impact on cos-mology, and could provide insight into the earliest moments (~10-32s) after the Big Bang. The presence of IGWs, or lack thereof, may disconfirm or confirm, respectively, the validity of the standard ΛCDM-model of cosmology, which does not include a period of inflation.
Heflin, Kylie Todd
"Inflationary Gravitational Waves and B-Mode Polarization of the Cosmic Microwave Background,"
Perpetua: The UAH Journal of Undergraduate Research: Vol. 1:
1, Article 5.
Available at: https://louis.uah.edu/perpetua/vol1/iss1/5