Testing ΛLTB as an alternative to dynamical dark energy

@misc{zhang2026testing,
  title = {{Testing $Λ$LTB as an alternative to dynamical dark energy}},
  author = {Yukang Zhang and Pengjie Zhang},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.05729},
  eprint = {2610.05729},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.05729},
}

TY  - UNPB
TI  - Testing ΛLTB as an alternative to dynamical dark energy
AU  - Yukang Zhang
AU  - Pengjie Zhang
PY  - 2026
DA  - 2026/10/05
PB  - arXiv
DO  - 10.48550/arxiv.2610.05729
UR  - https://arxiv.org/abs/2610.05729
AB  - A cosmological constant Λ in a universe weakly violating the cosmological principle (CP) can mimic a dynamical dark energy (DDE) in a FRW universe, and therefore challenging the recently reported DDE evidences. We test this scenario in the form of ΛLTB cosmology, against two data combinations. (1) DESI DR2 BAO, Planck CMB, together with any of the four SNe Ia compilations (UNION3, Pantheon+, DES SN5YR, and DES Dovekie) show no preference over DDE or ΛLTB. (2) The inclusion of the kinematic Sunyaev Zel'dovich (kSZ) effect rules out a large portion of the CP violation parameter space allowed by (1). However, the existence of a ∼ 300 Mpc/h region with ∼ 10% matter density excess is still allowed by the current data, and therefore remains a viable alternative to DDE. To facilitate further tests, we present analytical expressions of the distance-redshift relation and the kSZ effect in a universe with weak CP violation.
ER  -