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arXiv · 2407.15804

Coupled phantom cosmological model motivated by the warm inflationary paradigm

Sudip Halder·Supriya Pan·Paulo M. Sá·Tapan Saha
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Abstract

In this article, we investigate a coupled phantom dark-energy cosmological model in which the coupling term between a phantom scalar field with an exponential potential and a pressureless dark-matter fluid is motivated by the warm inflationary paradigm. Using methods of qualitative analysis of dynamical systems, complemented by numerical solutions of the evolution equations, we study the late-time behavior of our model. We show that contrary to the uncoupled scenario, the coupled phantom model admits accelerated scaling solutions. However, they do not correspond to a final state of the universe's evolution and, therefore, cannot be used to solve the cosmological coincidence problem. Furthermore, we show that, for certain coupling parameter values, the total equation-of-state parameter's asymptotic behavior is significantly changed when compared to the uncoupled scenario, allowing for solutions less phantom even for steeper potentials of the phantom scalar field.

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Sudip Halder, Supriya Pan, Paulo M. Sá, Tapan Saha. 2024-07-22. Coupled phantom cosmological model motivated by the warm inflationary paradigm. https://arxiv.org/abs/2407.15804

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