Thermal SZ effect in a magnetized IGM dominated by interacting DM decay/annihilation during dark ages

Abstract

During cosmic dawn, the thermal history of the universe is well studied, and a study of this era can give us some of the most useful insight into the universe before the recombination epoch. Its precise modeling and future high-precision measurements will be a valuable tool for determining the thermal history of the universe. In the present work, we study the thermal and ionization history of IGM in the presence of decaying magnetic fields via ambipolar and turbulent decay, Baryon-Dark matter (BDM) interaction, including the DM decay/annihilation. The BDM interaction cross-sections considered are of the form 𝜎 = 𝜎 0 𝑣 𝑛 , where 𝑛 = −2 and 𝑛 = −4. In this work, we show that in the current scenario, the decay/annihilation of the DM particles have a considerable impact on the temperature and ionization histories at low redshift. With the addition of the concept of fractional interaction, which states that if a fraction of the DM particles interacts with the baryons, the temperature and ionization fraction of the baryons show a strong dependence on the percentage of DM particles interacting with the baryons. We have also studied the interesting consequences of the present scenario on the thermal Sunyaev-Zeldovich (tSZ) effect. We show that the highest value of the absolute value of the mean 𝑦−parameter in the current DM decay/annihilation scenario is well within the values derived from experimental data such as PLANCK, FIRAS, and PIXIE. Later we calculate the bound on the ordinary magnetic fields originating from the Dark photons.