Analyzing the effect on CMB in a parity and charge-parity violating varying alpha theory

作者：Maity Debaprasad^*; Chen Pisin

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2012, 85(4): 043512.

DOI：10.1103/PhysRevD.85.043512

In this paper we study in detail the effect of our recently proposed model of parity and charge-parity (PCP) violating varying alpha on the Cosmic Microwave Background (CMB) photon passing through the intragalaxy-cluster medium (ICM). The ICM is well known to be composed of magnetized plasma. According to our model, the polarization and intensity of the CMB would be affected when traversing through the ICM due to nontrivial scalar photon interactions. We have calculated the evolution of such polarization and intensity collectively, known as the Stokes parameters of the CMB photon during its journey through the ICM and tested our results against the Sunyaev-Zel'dovich (SZ) measurement on the Coma galaxy cluster. Our model contains a PCP-violating parameter, beta, and a scale of alpha variation omega. Using the derived constrained on the photon-to-scalar conversion probability, (P) over bar (gamma ->phi), for the Coma cluster in [34,35] we found a contour plot in the (omega, beta) parameter plane. The beta = 0 line in this parameter space corresponds to well-studied Maxwell-dilaton type models which has lower bound on omega >= 6.4 x 10(9) GeV. In general, as the absolute value of beta increases, the lower bound on omega also increases. Our model in general predicts the modification of the CMB polarization with a nontrivial dependence on the parity-violating coupling parameter beta. However, it is unconstrained in this particular study. We show that this effect can in principle be detected in the future measurements on CMB polarization such that beta can also be constrained.

• 出版日期2012-2-14