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| Format: | Recurso digital |
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Zenodo
2025
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| Online Access: | https://doi.org/10.5281/zenodo.19657728 |
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Table of Contents:
- <p class="MsoNormal">This dissertation explores the role of dark energy in the accelerating expansion of the universe by conducting an in-depth statistical and visual analysis of 1,538 Type Ia supernovae from the Pantheon+SH0ES compilation, supplemented with high-precision photometric data from the Hubble Space Telescope (HST). Anchored in the ΛCDM (Lambda Cold Dark Matter) cosmological model, the study fulfills three primary objectives: (i) to investigate the correlation between redshift and apparent magnitude, (ii) to analyze variations in the distance modulus across redshift, and (iii) to identify and interpret acceleration signatures across different cosmological epochs. A strong and statistically significant positive correlation (r = 0.934, p < 0.001) was found between redshift and corrected B-band apparent magnitude (m<sub>b,corr</sub>), reinforcing the foundational principle of cosmic expansion. The low-redshift regime adheres closely to Hubble’s Law, while a pronounced upward curvature in the magnitude–redshift relation at z > 0.5 quantified by a second degree polynomial regression (R² = 0.972, c = 0.63 ± 0.01) provides robust observational evidence for late-time cosmic acceleration driven by dark energy. A binned analysis of the distance modulus (μSH0ES) reveals a systematic increase with redshift, consistent with expanding space-time, and further identifies curvature indicative of deviation from a linear Hubble flow. The segmentation of the dataset into three redshift epochs (low-z, mid-z, high-z) uncovers evolving expansion dynamics: a matter dominated decelerating phase at high redshifts, a transitional regime at intermediate redshifts, and a dark energy dominated accelerating phase in the low-z universe. The estimation of the deceleration parameter, q₀ = –0.58 ± 0.12, provides direct quantitative evidence for an accelerating universe, corroborating theoretical expectations from ΛCDM. These findings confirm the reliability of Type Ia supernovae as standard candles and validate their continued use in constraining key cosmological parameters such as the Hubble constant (H₀) and dark energy density (ΩΛ ≈ 0.71). Overall, this study provides compelling empirical support for the accelerating universe paradigm, deepens the understanding of dark energy’s role in cosmic evolution, and underscores the critical contributions of supernova cosmology to contemporary astrophysics.</p>