Dipolar dark matter and CMB B-mode polarization

Abstract

We consider dark matter particles as singlet fermionic particles carrying magnetic dipole moment to explore its contribution on the polarization of the cosmic microwave background (CMB) photons. We show that Dirac fermionic dark matter particles have no contribution on the CMB polarization. However, in the case of Majorana dark matter, this type of interaction leads to the B-mode polarization in the presence of primordial scalar perturbations which is in contrast with the standard scenario for the CMB polarization. We numerically calculate the B-mode power spectra and plot $$C_l^{BB}$$ClBB for different dark matter masses and the r-parameter. We show that dark matter particles with masses less than 100 MeV have a valuable contribution on $$C_l^{BB}$$ClBB. Meanwhile, dark matter particles with mass $$\text {m}_{\text {DM}}\le 50\, \text {MeV}$$mDM≤50MeV for $$r=0.07$$r=0.07 ( $$\text {m}_{\text {DM}}\le 80\, \text {MeV}$$mDM≤80MeV for $$r=0.09$$r=0.09) can be excluded experimentally. Furthermore, our results put a bound on the magnetic dipole moment about $$\text {M}\le 10^{-16} e\,\, \text {cm}$$M≤10-16ecm in agreement with the other reported constraints.

Freezing In with lepton flavored fermions

“…As can be seen, a significant region of the parameter space is already ruled out from XENON1T data with LZ and DARWIN projected to probe a much larger region of this model. There exist FIMP models that derive constraints from indirect detection experiments [14,100], CMB and astrophysics experiments [48,50,[101][102][103][104], and at colliders [105,106]. However, we estimate that these constraints do not probe the models studied in this work [107][108][109][110][111].…”

Freezing In with Lepton Flavored Fermions

“…As can be seen, a significant region of the parameter space is already ruled out from XENON1T data with DARWIN projected to probe a much larger region of this model. There exist FIMP models that derive constraints from indirect detection experiments [14,98], CMB and astrophysics experiments [47,49,[99][100][101][102], and at colliders [103,104]. However, we estimate that these constraints do not probe the models studied in this work [105][106][107][108][109].…”