Quintom scenario

Short description: Hypothetical form of dark energy

The Quintom scenario was proposed in 2004 by Xin-Min Zhang et al.,[1] and is a hypothetical model of dark energy. The name of 'quintom' was derived from 'quintessence' from quintessence field and 'phantom' from phantom dark energy. The Quintom scenario was to fit the evolution of dark energy with the cosmological data.

## Contents

* 1 Equation of state
* 2 Observational evidence
* 3 References
* 4 External links

## Equation of state

In this scenario, the equation of state (EoS) ω=p/ρ of the dark energy, relating its pressure and energy density, can cross the boundary ω=−1 associated with the cosmological constant. The boundary separates the phantom-energy-like behavior with ω<−1 from the quintessence-like behavior with ω>−1.

According to a no-go theorem, a single-field, single-fluid scalar model cannot cross ω=−1. Achieving such a crossing requires at least two degrees of freedom in dark energy models built from ideal fluids or scalar fields. To allow the effective equation of state to cross −1, possible approaches include:

* Multiple fields & extra degrees of freedom, e.g. additional scalar fields or fermion fields;
* Higher-order derivative terms, e.g. Galileon theory;
* Modified gravities, e.g. f(R), f(T), f(Q) gravity, metric-affine theory, or Horndeski gravity;
* Matter-dark energy interactions, e.g. interacting dark sector;
* Extra dimension effects, e.g. DGP gravity.

The Quintom scenario was applied in 2008 to produce a model of inflationary cosmology with a Big Bounce instead of a Big Bang singularity.

## Observational evidence

Current cosmological observations have given a clue in favor of the Quintom scenario. Since 2024, DESI has released the first year data and provided a possible "Quintom-B" scenario,[2] with the equation of state crossing the boundary from below to above.[3] The DESI data release 2 shows a deviation from the ΛCDM model compared with dynamical dark energy, preferring a Quintom-B behavior crossing ω=−1 from below to above.[4]

## References

1. ↑ Feng, Bo; Wang, Xiu-Lian; Zhang, Xin-Min (Apr 2004) "Dark energy constraints from the cosmic age and supernova." Physics Letter B 607: 35-41. astro-ph/0404224 [astro-ph] doi: 10.1016/j.physletb.2004.12.071
2. ↑ Gu, Gan; et al. (2025). "Dynamical Dark Energy in light of the DESI DR2 Baryonic Acoustic Oscillations Measurements". arXiv:2504.06118 [astro-ph.CO].
3. ↑ DESI Collaboration; Adame, A. G.; Aguilar, J.; Ahlen, S.; Alam, S.; Alexander, D. M.; Alvarez, M.; Alves, O. et al. (2024-11-04). "DESI 2024 VI: Cosmological constraints from the measurements of baryon acoustic oscillations". Journal of Cosmology and Astroparticle Physics 2025 (2): 021. doi:10.1088/1475-7516/2025/02/021.
4. ↑ Collaboration, DESI; et al. (2025). "DESI DR2 Results II: Measurements of Baryon Acoustic Oscillations and Cosmological Constraints". arXiv:2503.14738 [astro-ph.CO].

## External links

* Feng, Bo; Wang, Xiulian; Zhang, Xinmin (2005). "Dark energy constraints from the cosmic age and supernova". Physics Letters B 607 (1–2): 35–41. doi:10.1016/j.physletb.2004.12.071. Bibcode: 2005PhLB..607...35F.
* Kunz, Martin; Sapone, Domenico (2006). "Crossing the phantom divide". Physical Review D 74 (12). doi:10.1103/PhysRevD.74.123503. Bibcode: 2006PhRvD..74l3503K.
* Cai, Yi-Fu; Saridakis, Emmanuel N.; Setare, Mohammad R.; Xia, Jun-Qing (2010). "Quintom cosmology: Theoretical implications and observations". Physics Reports 493 (1): 1–60. doi:10.1016/j.physrep.2010.04.001. Bibcode: 2010PhR...493....1C.
* Qiu, Taotao (2010). "Theoretical Aspects of Quintom Models". Modern Physics Letters A 25 (11n12): 909–921. doi:10.1142/S021773231000006X. Bibcode: 2010MPLA...25..909Q.
* Cai, Yi-Fu; Qiu, Taotao; Xia, Jun-Qing; Li, Hong; Zhang, Xinmin (2009). "Model of inflationary cosmology without singularity". Physical Review D. 79 (2): 021303. doi:10.1103/PhysRevD.79.021303.

fr:Énergie fantôme it:Energia fantasma

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Quintom scenario. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Quintom_scenario&oldid=4335521"