8–12 Sept 2026
CBPF
America/Sao_Paulo timezone

What drives a high growth index? Insights from dark energy and varying G.

Not scheduled
20m
Auditório Ministro João Alberto Lins e Barros (CBPF)

Auditório Ministro João Alberto Lins e Barros

CBPF

Rua Dr. Xavier Sigaud, 150 - Urca Rio de Janeiro - RJ - Brasil CEP: 22290-180
Oral Talk

Speaker

Ronaldo Batista (Federal University of Rio Grande do Norte)

Description

Recent observational determinations of the cosmological growth index suggest values significantly higher than the standard ΛCDM prediction. I will discuss whether two cosmological scenarios can account for such high values. First, I will show that both homogeneous and clustering dark energy models face serious difficulties in producing elevated growth index values (arXiv:2411.00963). Next, I will show that varying-G parametrizations can yield such high values, implying a 2.4σ–3.4σ tension with the constant-G hypothesis, depending on the parametrization (arXiv:2510.15054). I will also address preliminary determinations of the growth index in the w₀wₐ parametrization using more recent cosmological data.

Authors

Prof. Leo Medeiros (Federal University of Rio Grande do Norte) Ronaldo Batista (Federal University of Rio Grande do Norte) Mr Ícaro Côrtes (Federal University of Rio Grande do Norte)

Presentation materials

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