Test of the Einstein equivalence principle with spectral distortions in the cosmic microwave background

作者：Arai Shun^*; Nitta Daisuke; Tashiro Hiroyuki

来源：PHYSICAL REVIEW D, 2016, 94(12): 124048.

DOI：10.1103/PhysRevD.94.124048

The Einstein equivalence principle (EEP) can be verified by the measurement of the spectral distortions of the cosmic microwave background (CMB). One of the consequences of the EEP on cosmological scales is the energy independency of the cosmological redshift effect. We propose a new test of the energy independency of the redshift effect by the measurement of the spectral distortion of CMB. In general relativity, the energy independency of the redshift effect is ensured by the Friedmann-Robertson-Walker (FRW) metric which does not depend on energy. We show that the CMB spectral distortions arise when the FRW metric has the energy dependence. Assuming the simple energy-dependent form of the FRW metric, we evaluate the CMB distortions. From the COBE/FIRAS bound, we find that the deviation degree from the EEP is, at least, less than 10(-5) at the CMB energy scales.

• 出版日期2016-12-28