Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

DESI 2024: Constraints on Physics-Focused Aspects of Dark Energy using DESI DR1 BAO Data

K. Lodha, A. Shafieloo, R. Calderon, E. Linder, W. Sohn, J. L. Cervantes-Cota, A. de Mattia, J. García-Bellido, M. Ishak, W. Matthewson, J. Aguilar, S. Ahlen, D. Brooks, T. Claybaugh, A. de la Macorra, A. Dey, B. Dey, P. Doel, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A Gontcho, C. Howlett, S. Juneau, S. Kent, T. Kisner, A. Kremin, A. Lambert, M. Landriau, L. Le Guillou, P. Martini, A. Meisner, R. Miquel, J. Moustakas, J. A. Newman, G. Niz, N. Palanque-Delabrouille, W. J. Percival, C. Poppett, F. Prada, G. Rossi, V. Ruhlmann-Kleider, E. Sanchez, E. F. Schlafly, D. Schlegel, M. Schubnell, H. Seo, D. Sprayberry, G. Tarlé, B. A. Weaver, H. Zou

TL;DR

This paper uses DESI DR1 BAO measurements, together with CMB and SN data, to test three physics-motivated dark energy behaviors—thawing, emergent (GEDE), and mirage. All three classes provide fits at least as good as ΛCDM, with the mirage model offering a competitive improvement and Bayes factors indicating a preference over ΛCDM for some SN datasets. Emergent GEDE remains largely ΛCDM-like when all data are included, while thawing shows dataset-dependent shifts in the equation of state parameters. The results suggest a richer dark energy sector with late-time emergence and possible w = −1 crossings, and they highlight the value of forthcoming DESI measurements to further constrain these scenarios.

Abstract

Baryon acoustic oscillation data from the first year of the Dark Energy Spectroscopic Instrument (DESI) provide near percent-level precision of cosmic distances in seven bins over the redshift range $z=0.1$-$4.2$. We use this data, together with other distance probes, to constrain the cosmic expansion history using some well-motivated physical classes of dark energy. In particular, we explore three physics-focused behaviors of dark energy from the equation of state and energy density perspectives: the thawing class (matching many simple quintessence potentials), emergent class (where dark energy comes into being recently, as in phase transition models), and mirage class (where phenomenologically the distance to CMB last scattering is close to that from a cosmological constant $Λ$ despite dark energy dynamics). All three classes fit the data at least as well as $Λ$CDM, and indeed can improve on it by $Δχ^2\approx -5$ to $-17$ for the combination of DESI BAO with CMB and supernova data, while having one more parameter. The mirage class does essentially as well as $w_0w_a$CDM while having one less parameter. These classes of dynamical behaviors highlight worthwhile avenues for further exploration into the nature of dark energy.

DESI 2024: Constraints on Physics-Focused Aspects of Dark Energy using DESI DR1 BAO Data

TL;DR

This paper uses DESI DR1 BAO measurements, together with CMB and SN data, to test three physics-motivated dark energy behaviors—thawing, emergent (GEDE), and mirage. All three classes provide fits at least as good as ΛCDM, with the mirage model offering a competitive improvement and Bayes factors indicating a preference over ΛCDM for some SN datasets. Emergent GEDE remains largely ΛCDM-like when all data are included, while thawing shows dataset-dependent shifts in the equation of state parameters. The results suggest a richer dark energy sector with late-time emergence and possible w = −1 crossings, and they highlight the value of forthcoming DESI measurements to further constrain these scenarios.

Abstract

Baryon acoustic oscillation data from the first year of the Dark Energy Spectroscopic Instrument (DESI) provide near percent-level precision of cosmic distances in seven bins over the redshift range -. We use this data, together with other distance probes, to constrain the cosmic expansion history using some well-motivated physical classes of dark energy. In particular, we explore three physics-focused behaviors of dark energy from the equation of state and energy density perspectives: the thawing class (matching many simple quintessence potentials), emergent class (where dark energy comes into being recently, as in phase transition models), and mirage class (where phenomenologically the distance to CMB last scattering is close to that from a cosmological constant despite dark energy dynamics). All three classes fit the data at least as well as CDM, and indeed can improve on it by to for the combination of DESI BAO with CMB and supernova data, while having one more parameter. The mirage class does essentially as well as CDM while having one less parameter. These classes of dynamical behaviors highlight worthwhile avenues for further exploration into the nature of dark energy.
Paper Structure (15 sections, 8 equations, 8 figures, 4 tables)

This paper contains 15 sections, 8 equations, 8 figures, 4 tables.

Table of Contents

  1. Introduction
  2. Physics-focused classes
  3. Dark Energy Equation of State: Thawing Physics
  4. Dark Energy Density: Emergent Physics
  5. Dark Energy: Mirage Physics
  6. Data and Methodology
  7. Results and Discussions
  8. Thawing
  9. Generalized Emergent Dark Energy
  10. Mirage
  11. Comparison and Discussion
  12. Conclusion
  13. Thawing Class: Calibration vs Algebraic Forms
  14. Supernova Data Comparison
  15. Author Affiliations

Figures (8)

  • Figure 1: Marginalized constraints within the thawing class of dark energy described by \ref{['eq:thaw-scale']}, from different combinations of data sets.
  • Figure 2: Marginalized constraints on the dark energy equation of state $w(z)$ and energy density $f_{\rm DE}(z)$ for the thawing class, parametrized by \ref{['eq:thaw-scale']}.
  • Figure 3: Marginalized constraints within the Generalized Emergent Dark Energy (GEDE) class described by \ref{['eq:GEDE']}.
  • Figure 4: Marginalized constraints on the dark energy equation of state $w(z)$ and energy density $f_{\rm DE}(z)$ for the GEDE model, parametrized by \ref{['eq:GEDE']}.
  • Figure 5: Marginalized constraints within the mirage class of dark energy described by \ref{['eq:mirage']}.
  • ...and 3 more figures