2023/12/23 by Albert Munyeshyaka, Joseph Ntahompagaze, Munyeshyaka, Albert +5 · 3 citations
Earth and Planetary Sciences · Physics and Astronomy · #83D05 #83F05 #Cosmology and Gravitation Theories #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #Solar and Space Plasma Dynamics
paper · pdf · doi:10.48550/arxiv.2312.15183
openalex publication_date 2023/12/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate cosmological perturbations of f(G) gravity in the presence of a scalar field. Using the 1 + 3 covariant formalism, we present the energy overdensity perturbation equations responsible for large scale structure formation. After applying harmonic decomposition method together with the redshift transformation technique, we obtain the fully perturbed equations in redshift space. The equations are solved to study the growth of matter overdensities contrast with redshift. For both short- and long-wavelength modes, we obtain numerical results for particular functional form f(G) models and scalar field. We find that, for this choice the energy overdensity perturbations decay with increase in redshift. However, for both short- and long- wavelength modes, the perturbations which include amplitude effects due to the f(G) models with a scalar field do differ remarkably from those in Lambda CDM. The results reduce to GR results in the limit of f(G) tends to G and in the absence of scalar field.