Constraints on Asymmetric Dark Matter in Quintessence Model

The modified cosmology like quintessence model with kination phase predicted the Hubble expansion rate of the universe before Big Bang Nucleosynthesis is different from the standard cosmological scenario. The modified expansion rate leaves its imprint on the relic density of asymmetric dark matter. In this work, we review the calculation of relic density of asymmetric WIMP dark matter in the standard cosmological scenario and quintessence model with kination phase. Then we use the Planck data to find constraints on the annihilation cross section and the mass of the asymmetric dark matter in those models.

Asymmetric dark matter and Sommerfeld enhancement

We study the relic density of asymmetric dark matter with long-range interactions by considering the Sommerfeld effect. We find that the annihilation cross section of asymmetric dark matter is enhanced by the Sommerfeld effect and thus the relic density is decreased. Then we use the Planck data to constrain the asymmetry factor, coupling, and to derive the upper bounds on the dark matter mass in s-wave and p-wave annihilation cases.

Relic density of asymmetric Dark Matter with Sommerfeld enhancement

We investigate the evolution of abundance of the asymmetric thermal Dark Matter when its annihilation rate at chemical decoupling is boosted by the Sommerfeld enhancement.Next,we discuss the effect of kinetic decoupling on the relic abundance of asymmetric Dark Matter when the interaction rate depends on velocity.Usually,the relic den sity of asymmetric Dark Matter is analyzed in the frame of chemical decoupling.In deed,after decoupling from chemical equilibrium,asymmetric Dark Matter particles and anti-particles are still in kinetic equilibrium for a while.This has no effect for the case of 5-wave annihilation since there is no temperature dependenee in this case.However,kinetic decoupling has impacts for the case of p-wave annihilation and Sommerfeld enhanced s-and p-wave annihilations.We investigate in detail the extent to which kinetic decoupling affects the relic abundanee of asymmetric Dark Matter particles and anti-particles.We find the constraints on the cross section and asymmetry factor using observational data of the relic density of Dark Matter.

Asymmetric dark matter abundance including non-thermal production

We investigate the relic abundance of asymmetric dark matter where the asymmetric dark matter is non–thermally produced from the decay of heavier particles in addition to the usual thermal production.We discuss the relic density of asymmetric dark matter including the decay of heavy particles in low-temperature scenarios.Here,we still assume that the Universe is radiationdominated and there is asymmetry before the decay of heavy particles.We obtain an increased abundance of asymmetric dark matter when there is an additional contribution from the decay of heavier particles.Finally,we find the constraints on the asymmetry factor and annihilation crosssection using Planck data.

Abundance of Asymmetric Dark Matter in Brane World Cosmology

Relic abundance of asymmetric Dark Matter particles in brane world cosmological scenario is investigated in this article. Hubble expansion rate is enhanced in brane world cosmology and it affects the relic abundance of asymmetric Dark Matter particles. We analyze how the relic abundance of asymmetric Dark Matter is changed in this model. We show that in such kind of nonstandard cosmological scenario, indirect detection of asymmetric Dark Matter is possible if the cross section is small enough which let the anti-particle abundance kept in the same amount with the particle. We show the indirect detection signal constraints can be used to such model only when the cross section and the 5-dimensional Planck mass scale are in appropriate values.

Twin cogenesis

We investigate a cogenesis mechanism within the twin Higgs setup that can naturally explain the nature of dark matter,the cosmic coincidence puzzle,little hierarchy problem,leptogenesis,and the tiny neutrino masses.Three heavy Majorana neutrinos are introduced to the standard model sector and the twin sector respectively,which explain the tiny neutrino masses and generate the lepton asymmetry and the twin lepton asymmetry at the same time.The twin cogenesis mechanism applies to any viable twin Higgs model without an explicit Z_(2)breaking in the leptonic sector and evading theΔN_(eff) constraint.We illustrate the twin cogenesis mechanism using the neutrino-philic twin two Higgs doublet model,a newly proposed model to lift the twin neutrino masses with spontaneous Z_(2)breaking.The dark photon with a Stueckelberg mass O(10)MeV ensures the energy in the twin sector as well as the symmetric component of twin sector particles can be depleted.The lightest twin baryons are the dark matter candidates with masses of approximately 5.5 GeV,which explains naturally the amount of dark matter and visible matter in the Universe are of the same order.We also demonstrate twin cogenesis in the fraternal twin Higgs setup,in which the dark matter candidate is the twin bottom bound stateΩ’_(b’b’b’).