제목: Towards a New Paradigm in Supernova Cosmology​​​

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​​​​​​​​​​​​​​​​​​연사: Prof. Young-Wook Lee (Yonsei University)​​​​​​​​​​​​

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일시: 2026년 3월 13일 금요일 11:00

장소: 과학관 B101​​

Abstract:

​Supernova (SN) cosmology is based on the key assumption that the luminosity standardization process of Type Ia SNe remains invariant with progenitor age. However, direct and extensive age measurements of SN host galaxies reveal a significant correlation between standardized SN magnitude and progenitor age, which is expected to introduce a serious bias with redshift in SN cosmology. This systematic bias is largely uncorrected by the commonly used mass-step correction, as progenitor age and host galaxy mass evolve very differently with redshift. After correcting for this age bias as a function of redshift, the SN dataset aligns more closely with the wowaCDM model recently suggested by the DESI BAO project from a combined analysis using only BAO and CMB data. When the three cosmological probes (SNe, BAO, and CMB) are combined, we find a significantly stronger (> 9 σ) tension with the LCDM model than that reported in the DESI papers, suggesting a time-varying dark energy equation of state in a currently non-accelerating universe. Finally, we discuss how these findings motivate new strategies and directions for precision cosmology with SNe Ia in the LSST era.