- Modelling the expulsion of baryons from haloes
from first principles: the role of feedback and of the cosmological constant:
Veenema et al 2026:
Oscar Veenema, Daniele Sorini, Sownak Bose
arXiv,
2026,
Mar13,
21 pages:
Research: On
cosmological constant Λ,
dark energy (Λ)
dark matter halos,
baryonic matter, and
missing baryon problem
(AKA missing mass problem):
"In cosmologies with Λ>&Lambda_0, dark energy emerges as the dominant factor
in this process -- suggesting that, as our Universe transitions towards Λ-domination,
dark energy eventually becomes the primary driver of baryon evacuation from massive haloes."
- keywords_cosmology.html.
- missing baryon problem in halos
(see McGaugh et al. 2010).
The missing baryon problem in halos
is that the in
dark matter halos
the baryon fraction f=Ω_b/&Omega_(b-cosmic) < 1.
In galaxies
f=Ω_b/&Omega_(b-cosmic) < 0.03 and has
dark matter halos get bigger
f=Ω_b/&Omega_(b-cosmic) approaches 1 for the largest
galaxy clusters.
See also
Wikipedia: Missing baryon problem,
but this NOT the
missing baryon problem in haloes.
- virial radius R_200:
See also Wikipedia: Virial mass
- 003_cosmos/notes_3065_3098_2026jan24.pdf#page=7: The Cosmological Constant Force: p. 7--21.
- 003_cosmos/notes_3065_3098_2026jan24.pdf#page=15:
turnaround radius where f_grav=f_λ:
The
turnaround radius is
NOT the virial radius R_200
NOT the critical radius in general, but is the simplified one for
Veenema et al 2026, p. 4,
and NOT the
closure radius of
Veenema et al 2026, p. 4 (definition), 5 (derivation),
6 (formula).
- Cosmology file:
cosmic_scale_factor.html