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arXiv · 2504.09649

Galaxy Mergers in a Fractal Cosmology

Bruno J. Souza·Osvaldo L. Santos-Pereira·Marcelo B. Ribeiro
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Abstract

This work discusses the influence of galaxy mergers in the evolution of a parabolic Lema\^{\i}tre-Tolman-Bondi (LTB) cosmology with simultaneous big bang endowed with two consecutive single fractal galaxy distributions systems possessing fractal dimension $D$. Based on recent empirical findings, it is assumed that the resulting galaxy mass from mergers can be expressed by a redshift dependent decaying power law. The proposed cosmological model modifies the relativistic fractal number counts distribution by including a merger rate evolution that estimates the model's radial density. Numerical solutions for the first order small-merger-rate approximation (SMRA) are found and the results show that a fractal galaxy distribution having $D=1.5$ in the range $0.1<z<1.0$, and $D=0.5$ for $1<z<6$, as suggested by recent empirical findings, the SMRA allows consistent description of the model for a merger rate power law exponent up to $q=0.2$ considering a fractal galaxy distribution starting from the Local Group. Consistent values were also found up to $q=2.5$ and $z=7$ from a scale smaller than the Local Supercluster. These results show that galaxy mergers can be successfully incorporated into the dynamics of a parabolic LTB fractal cosmology.

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Bruno J. Souza, Osvaldo L. Santos-Pereira, Marcelo B. Ribeiro. 2025-04-13. Galaxy Mergers in a Fractal Cosmology. https://doi.org/10.1140/epjc%2Fs10052-025-14191-0

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