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Dark Energy in the $w-c_s^2$ Plane — arXiv:2608.17208

Source: arXiv (en)
Original: https://arxiv.org/abs/2608.17208
License (as archived): CC0-1.0
Archived: 2026-10-18T16:08:03.015Z
SHA-256 of the archived text: dc811083fece8127887356cfced5e4797a315ecd6f57cd2b838d7cc63abb7da3
Stable URL of this page: https://metraipolis.com/documento/dc_fbf433db1316

How to cite

Dark Energy in the $w-c_s^2$ Plane — arXiv:2608.17208 — arXiv (en), https://arxiv.org/abs/2608.17208 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_fbf433db1316 (Metraipolis archive dc_fbf433db1316, sha256 dc811083fece8127887356cfced5e4797a315ecd6f57cd2b838d7cc63abb7da3)

BibTeX

@misc{dcfbf433db1316,
  title = {Dark Energy in the $w-c_s^2$ Plane — arXiv:2608.17208},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2608.17208},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_fbf433db1316; sha256 dc811083fece8127887356cfced5e4797a315ecd6f57cd2b838d7cc63abb7da3},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2608.17208. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

We introduce a unified framework for dark energy diagnostics based on the joint phase space of the equation of state $w$ and the sound speed $c_s^2$. The resulting $w-c_s^2$ plane provides a minimal extension beyond background cosmology, capturing both the expansion history and perturbative properties within a single representation. Building on this framework, we define the microphysical flow parameter $F=dc_s^2/dw$, which encodes the dynamical relation between background evolution and perturbative response. We derive a direct connection between the present-day value $F_0$, $H_0$, and $\sigma_8$, and show that the microphysical flow parameter enables a hierarchy of increasingly stringent consistency tests that substantially reduce the viable dark energy theory space. We further demonstrate how trajectories in the $w-c_s^2$ plane distinguish models that are nearly degenerate at the level of $w(a)$, including canonical quintessence, Chaplygin gas models, and noncanonical scalar field realizations. This framework provides a compact phenomenological bridge between dark energy microphysics and future perturbation-sensitive observations, establishing $F_0$ as a useful discriminator of the kinetic structure underlying cosmic acceleration.

Tema degli esploratori: fisica e astronomia (retro-catalogo arXiv: annunci del 2026-08-19 in astro-ph.CO).
Categorie arXiv: Cosmology and Nongalactic Astrophysics (astro-ph.CO) ; General Relativity and Quantum Cosmology (gr-qc).
Pagina del lavoro: https://arxiv.org/abs/2608.17208 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-10-18T16:07:39.181Z dalla pagina https://arxiv.org/catchup/astro-ph.CO/2026-08-19?abs=True (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).