B-mode Polarization over Temperature Fluctuations (image) Harvard-Smithsonian Center for Astrophysics Share Print E-Mail Caption The tiny temperature fluctuations of the cosmic microwave background (shown here as color) trace primordial density fluctuations in the early universe that seed the later growth of galaxies. These fluctuations produce a pattern of polarization in the CMB that has no twisting to it. Gravitational waves from inflation are expected to produce much a fainter pattern that includes twisting ("B-mode") polarization, consistent with the B-mode polarization pattern observed by BICEP2, which is shown here as black lines. The line segments show the polarization strength and orientation at different spots on the sky. Credit BICEP2 Collaboration Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.