https://neckpinch.com/authors/christian-corda/New arXiv papers by Christian Corda, from Neckpinch Tue, 03 Nov 2026 08:41:12 GMT https://neckpinch.com/papers/2504.14609/arxiv:2504.14609Sun, 20 Apr 2025 00:00:00 GMTStuart Marongwe, Stuart Kauffman, Moletlanyi Tshipa, Christian Corda — The S₈ parameter, which quantifies the amplitude of matter fluctuations on scales of 8h⁻¹ Mpc, has been a source of tension between weak lensing surveys (e.g. KiDS, DES, HSC) and the Planck Cosmic Microwave Background (CMB) measurements. This discrepancy challenges the standard ΛCDM model and has become one of the most significant tensions in modern cosmology. The Λ' model offers a potential resolution by introducing modifications to the cosmic growth history through alterations to the gravitational sector. The alterations involve including a Ricci soliton into Einstein's field equations which introduce a time dependent factor yielding a time varying cosmological constant Λ'=(1-α(t)²Λ_DEfracρ_gρ_DE and subsequently the evolution of the cosmos. The Ricci soliton is sourced from gravitational energy density. In this study we analyze results from six surveys and compare the results for wₐ and w₀ with the Λ' model. We also find σ₈=0.750_(−0.020)^(+0.020) , S₈=0.788. These values are closer to some low S₈ measurements from weak lensing surveys (e.g DES, KiDS), which report S₈ ≈ 0.76-0.78, suggesting that the model may alleviate the S₈ tension. High values of α(t) in the late universe are the cause of suppressed structure formation and low values of Λ'. The late universe in the Λ' model is effectively or apparently 5-10% younger than in ΛCDM which translates to H₀=72.734_(−1.687)^(+1.687) km/s/Mpc, which is in agreement with late universe probes. Λ' is classified under the dynamical dark energy models, however unlike alternatives, it does not invoke exotic particles nor phantom energy.Ricci solitonsPhysics