Tensor-induced B modes with no temperature fluctuations

Abstract

The recent indications for a tensor-to-scalar ratio $r\simeq 0.2$ from BICEP2 measurements of the cosmic microwave background (CMB) B-mode polarization present some tension with upper limits $r\lesssim 0.1$ from measurements of CMB temperature fluctuations. Here we point out that tensor perturbations can induce B modes in the CMB polarization without inducing any temperature fluctuations nor E-mode polarization whatsoever, but only, at the expense of violating the Copernican principle. We present this mathematical possibility as a new ingredient for the model-builder's toolkit in case the tension between B modes and temperature fluctuations cannot be resolved with more conventional ideas.

4 pages, published version in PRD

References in corpus (2)

• A Measurement of the Cosmic Microwave Background Damping Tail from the 2500-square-degree SPT-SZ survey
• Total Angular Momentum Waves for Scalar, Vector, and Tensor Fields

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