Constraining Single Dark Matter Particle Mass by Primordial Gravitational Wave. (arXiv:1902.05738v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Li_C/0/1/0/all/0/1">Changhong Li</a>
We report on a new relation between dark matter (DM) particle mass, $m_chi$,
and the tensor-to-scalar ratio of cosmic microwave background (CMB)
anisotropies, $r$. Once $r$ is determined in a future search of primordial
gravitational wave (PGW), $m_chi$ can be constrained by using this relation.
Due to the resonance interplay between metric and DM density perturbations, a
small local fluctuation of spacetime can be generated in a pair production of
DM particles. Such fluctuations, arising from the DM pair productions, encode
information of DM mass and slightly change the amplitude of metric
perturbation. Within a general framework of cosmic reheating, we show that,
these fluctuations are accumulated during DM production process, which
amplifies the scalar modes of metric perturbation significantly and results in
a strong suppression of $r$. Thus we establish a novel link between DM and PGW,
which yields a new relation between $m_chi$ and $r$. For illustration, in a
toy model of cosmic reheating with $alpha=10^{-8}$, we show that
$m_chi=10~text{GeV}$ if PGW is detected at $r=0.3times 10^{-2}$.
We report on a new relation between dark matter (DM) particle mass, $m_chi$,
and the tensor-to-scalar ratio of cosmic microwave background (CMB)
anisotropies, $r$. Once $r$ is determined in a future search of primordial
gravitational wave (PGW), $m_chi$ can be constrained by using this relation.
Due to the resonance interplay between metric and DM density perturbations, a
small local fluctuation of spacetime can be generated in a pair production of
DM particles. Such fluctuations, arising from the DM pair productions, encode
information of DM mass and slightly change the amplitude of metric
perturbation. Within a general framework of cosmic reheating, we show that,
these fluctuations are accumulated during DM production process, which
amplifies the scalar modes of metric perturbation significantly and results in
a strong suppression of $r$. Thus we establish a novel link between DM and PGW,
which yields a new relation between $m_chi$ and $r$. For illustration, in a
toy model of cosmic reheating with $alpha=10^{-8}$, we show that
$m_chi=10~text{GeV}$ if PGW is detected at $r=0.3times 10^{-2}$.
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