(P)reheating after minimal Plateau Inflation and constraints from CMB. (arXiv:1811.11173v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Maity_D/0/1/0/all/0/1">Debaprasad Maity</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Saha_P/0/1/0/all/0/1">Pankaj Saha</a>
We have studied the preheating phase for a class of plateau inflationary
model considering the four-legs interaction term $(1/2)g^2phi^2chi^2$ between
the inflaton $(phi)$ and reheating field $(chi)$. We specifically focus on
the detailed effect of a parameter $phi_{ast}$ that controls inflationary
dynamics and the shape of the inflaton potential. For $phi_{ast} < M_p$, the
departure of the inflaton potential from the usual power-law behavior $phi^n$
significantly modifies the microscopic behavior of the preheating dynamics. We
analyze and compare in detail the efficiency of production, thermalization and
the final equation of state of the system for different models under
consideration with $n=2,4,6$ for two different values of $phi_{ast}$. Most
importantly as we increase $n$, or decrease $phi_{ast}$, the preheating
occurs very efficiently with the final equation of state to be that of the
radiation, $w=1/3$. Specially for $n=2$, the final equation of state turned out
to be $wsimeq 0.2$. However, a complete decay of inflaton could not be
achieved with the four-legs interaction for any model under consideration.
Therefore, in order to complete the reheating process, we perform the
perturbative analysis for the second stage of the reheating phase. Taking the
end product of the preheating phase as an initial condition we have solved the
homogeneous Boltzmann equations for both the fields supplemented by the
constraints coming from the subsequent entropy conservation. In so doing, we
are able to calculate the reheating temperature which is otherwise ill-defined
right after the end of preheating. The temperature can be uniquely fixed for a
given inflaton decay constant and the CMB temperature. We also compare our
results with the conventional reheating constraint analysis and discuss the
limit of inflaton decay constant from the field theory perspective.
We have studied the preheating phase for a class of plateau inflationary
model considering the four-legs interaction term $(1/2)g^2phi^2chi^2$ between
the inflaton $(phi)$ and reheating field $(chi)$. We specifically focus on
the detailed effect of a parameter $phi_{ast}$ that controls inflationary
dynamics and the shape of the inflaton potential. For $phi_{ast} < M_p$, the
departure of the inflaton potential from the usual power-law behavior $phi^n$
significantly modifies the microscopic behavior of the preheating dynamics. We
analyze and compare in detail the efficiency of production, thermalization and
the final equation of state of the system for different models under
consideration with $n=2,4,6$ for two different values of $phi_{ast}$. Most
importantly as we increase $n$, or decrease $phi_{ast}$, the preheating
occurs very efficiently with the final equation of state to be that of the
radiation, $w=1/3$. Specially for $n=2$, the final equation of state turned out
to be $wsimeq 0.2$. However, a complete decay of inflaton could not be
achieved with the four-legs interaction for any model under consideration.
Therefore, in order to complete the reheating process, we perform the
perturbative analysis for the second stage of the reheating phase. Taking the
end product of the preheating phase as an initial condition we have solved the
homogeneous Boltzmann equations for both the fields supplemented by the
constraints coming from the subsequent entropy conservation. In so doing, we
are able to calculate the reheating temperature which is otherwise ill-defined
right after the end of preheating. The temperature can be uniquely fixed for a
given inflaton decay constant and the CMB temperature. We also compare our
results with the conventional reheating constraint analysis and discuss the
limit of inflaton decay constant from the field theory perspective.
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