Pith. sign in

REVIEW 4 cited by

The dark degeneracy: On the number and nature of dark components

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv astro-ph/0702615 v2 pith:6KFJMQO7 submitted 2007-02-22 astro-ph

classification astro-ph
keywords darkdegeneracyenergymodelsfamilyomegaveryactual
verification ladder T0 review T1 audit T2 compute T3 formal
0 comments
read the original abstract

We use that gravity probes only the total energy momentum tensor to show how this leads to a degeneracy for generalised dark energy models. Because of this degeneracy, Omega_m cannot be measured. We demonstrate this explicitely by showing that the CMB and supernova data is compatible with very large and very small values of Omega_m for a specific family of dark energy models. We also show that for the same reason interacting dark energy is always equivalent to a family of non-interacting models. We argue that it is better to face this degeneracy and to parametrise the actual observables.

Discussion (0). Sign in to comment.

Forward citations

Cited by 4 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. The silent dark sector: a field-theory approach to unified dark fluids with vanishing speed of sound

    astro-ph.CO 2026-07 conditional novelty 6.0 of 10

    All vanishing-speed-of-sound TDiff scalar theories reduce to a two-parameter mimetic action describing the dark sector as interacting dust plus vacuum; a quadratic-potential example tracks the DESI CPL background.

  2. Defocusing dark energy: Raychaudhuri diagnostics beyond $w<-1/3$ and the phantom divide

    gr-qc 2026-07 accept novelty 6.0 of 10

    For sign-changing effective dark energy, smooth negative-to-positive density crossings make ρ+3p and ρ+p the correct diagnostics, give w=p/ρ a universal pole n(1+z†)/3, and force repulsion onset z_rep>z† while ρ<0.

  3. Breaking the Dark Sector Degeneracy with Nonparametric Expansion--Growth Reconstruction

    astro-ph.CO 2026-07 unverdicted novelty 6.0 of 10

    Joint nonparametric expansion–growth reconstruction finds no significant dark-sector interaction or dark-energy dynamics, remaining consistent with ΛCDM over 0≲z≲2.

  4. Is Dark Matter Really Matter?

    astro-ph.CO 2026-08 conditional novelty 5.0 of 10

    Using DESI DR2, DES supernovae, and two CMB likelihoods, the authors find wDM about 0.001 and wDE about -0.94 when varied jointly, a roughly 2-sigma joint preference away from Lambda-CDM, with a non-phantom Pade-w plu...

Pith tools