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arXiv · 2501.09177

Cosmological Interactions with Phantom Scalar Field: Revisiting Background Phase-Space Analysis with Compactified Variables

Genly Leon·Daya Shankar·Amlan Halder·Andronikos Paliathanasis
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Abstract

Energy transfer in the dark sector of the universe gives rise to new phenomena of special interest in modern cosmology. When dark energy is modeled as a phantom scalar field, interactions become crucial to avoid Big Rip singularities. In this work, we revisit the phase-space analysis of the field equations by introducing a new set of dimensionless variables distinct from the traditional Hubble normalization approach. These new variables define a compactified phase space for the evolution of physical parameters. We demonstrate that these compactified variables offer fresh insights into the phase-space analysis in gravitational theories, particularly when the dark energy fluid is allowed to possess a negative kinetic energy density.

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Genly Leon, Daya Shankar, Amlan Halder, Andronikos Paliathanasis. 2025-01-15. Cosmological Interactions with Phantom Scalar Field: Revisiting Background Phase-Space Analysis with Compactified Variables. https://arxiv.org/abs/2501.09177

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