English

Generalizing the interacting dilatonic ghost condensate as a dark energy model

General Relativity and Quantum Cosmology 2026-06-26 v1 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

In this article, we study the cosmic evolution of a generalized dilatonic ghost condensate field as a dark energy candidate, formulated from a Lagrangian density with two dominant kinetic terms; one linear and one of arbitrary integer n>2n>2 in combination with an exponential potential, which interacts with dark matter through a source term. We analyzed three scenarios: the non-interacting situation Q=0Q=0 and two different interaction models, Qρmϕ˙Q\propto\rho_m\dot{\phi} and QρmHQ\propto \rho_m H to describe the evolution of the present universe. For each interaction QQ, we perform a detailed phase-space analysis to obtain stability conditions and identify critical points. In all situations, the system reproduces the standard cosmological dynamics and evolves toward late-time dark energy-dominated attractors, with quintessence or phantom features depending on the sign of the coupling parameter α\alpha associated with the standard kinetic term. Furthermore, a joint likelihood analysis with Cosmic Chronometers, PantheonPlus, and DESI observations is performed for two values of power nn (n=3n=3 and n=5n=5) to determine marginalized parameter constraints at the confidence levels of 68%\% and 95%\% for the different QQ-models. For the interaction term Qϕ˙ρmQ\propto \dot{\phi}\rho_m, we find that the direction of the flow of energy depends on the sign of the coupling parameter α\alpha associated with the standard kinetic term. However, for the interaction QHρmQ\propto H\,\rho_m, the direction of the energy flow is independent of the sign of the coupling parameter α\alpha and always remains negative, corresponding to an energy transfer from dark matter to dark energy.

Cite

@article{arxiv.2606.28288,
  title  = {Generalizing the interacting dilatonic ghost condensate as a dark energy model},
  author = {Manuel Gonzalez-Espinoza and Ramon Herrera and Johan Casimiro},
  journal= {arXiv preprint arXiv:2606.28288},
  year   = {2026}
}

Comments

28 pages, 5 figures

R2 v1 2026-07-22T20:11:31.685Z