TY - JOUR

T1 - The mass of our observable Universe

AU - Gaztañaga, Enrique

N1 - Funding Information:
We acknowledge grants from Spain Plan Nacional (PGC2018- 102021-B-100) and Maria de Maeztu (CEX2020-001058-M).
Publisher Copyright:
© 2023 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society.

PY - 2023/5/1

Y1 - 2023/5/1

N2 - The standard cosmological model Lambda Cold Dark Matter (LCDM) assumes a global expanding space-time of infinite extent around us. But such idea is inconsistent with the observed cosmic acceleration unless we advocate for the existence of a mysterious dark energy (DE) or a cosmological constant (Λ). Here, we argue instead that our Universe has a very large but finite regular mass M, without the need to invoke DE or Λ. A system with a finite mass M has a finite gravitational radius rS = 2GM. When M is contained within rS, this is a black hole (BH). Nothing from inside can escape outside rS, which becomes a boundary for the inside dynamics. In the limit where there is nothing else outside, the inside corresponds then to a local isolated universe. Such boundary condition is equivalent to a Λ term: $\Lambda =3/r_{S}2$. We can therefore interpret cosmic acceleration as a measurement of the gravitational radius of our Universe, rS, with a mass M ≃ 6 × 1022 M⊙. Such BH Universe is observationally very similar to the LCDM, except for the lack of the largest scale perturbations, which are bounded by rS.

AB - The standard cosmological model Lambda Cold Dark Matter (LCDM) assumes a global expanding space-time of infinite extent around us. But such idea is inconsistent with the observed cosmic acceleration unless we advocate for the existence of a mysterious dark energy (DE) or a cosmological constant (Λ). Here, we argue instead that our Universe has a very large but finite regular mass M, without the need to invoke DE or Λ. A system with a finite mass M has a finite gravitational radius rS = 2GM. When M is contained within rS, this is a black hole (BH). Nothing from inside can escape outside rS, which becomes a boundary for the inside dynamics. In the limit where there is nothing else outside, the inside corresponds then to a local isolated universe. Such boundary condition is equivalent to a Λ term: $\Lambda =3/r_{S}2$. We can therefore interpret cosmic acceleration as a measurement of the gravitational radius of our Universe, rS, with a mass M ≃ 6 × 1022 M⊙. Such BH Universe is observationally very similar to the LCDM, except for the lack of the largest scale perturbations, which are bounded by rS.

KW - black hole physics

KW - dark energy

UR - http://www.scopus.com/inward/record.url?scp=85153768891&partnerID=8YFLogxK

U2 - 10.1093/mnrasl/slad015

DO - 10.1093/mnrasl/slad015

M3 - Article

AN - SCOPUS:85153768891

SN - 1745-3925

VL - 521

SP - L59-L63

JO - Monthly Notices of the Royal Astronomical Society: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

IS - 1

ER -