7 papers
Still non-accelerating: age-bias correction in supernova cosmology is robust to host-progenitor age mapping
Chul Chung, Junhyuk Son, Seunghyun Park +4
We re-examine the claim by Wiseman et al. (2026) that progenitor-age bias has a negligible impact on cosmological inferences from Type Ia supernovae (SNe Ia). We show that their in…
How Robust is the Cosmic Distance with Tip of Red Giant Branch against Stellar Population Variations?
Chul Chung, Young-Wook Lee, Suk-Jin Yoon +10
The tip of the red giant branch (TRGB) provides a key standard candle for extragalactic distance measurements and for refining the Hubble constant. We test its robustness by quanti…
Strong Progenitor Age-bias in Supernova Cosmology. II. Alignment with DESI BAO and Signs of a Non-Accelerating Universe
Junhyuk Son, Young-Wook Lee, Chul Chung +2
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 extens…
Near-Infrared Spectroscopy with IGRINS-2 for Studying Multiple Stellar Populations in Globular Clusters
Dongwook Lim, Young-Wook Lee, Sol Yun +53
Recent advancements in near-infrared (NIR) spectroscopy have opened new opportunities for studying multiple stellar populations in globular clusters (GCs), particularly for newly d…
Strong progenitor age bias in supernova cosmology. I. Robust and ubiquitous evidence from a larger sample of host galaxies in a broader redshift range
Chul Chung, Seunghyun Park, Junhyuk Son +2
Type Ia supernovae (SNe Ia) serve as the most crucial standardizable candles in cosmology, providing direct measurements of the universe's expansion history. However, it is well-kn…
Comparison of chemical compositions between the bright and faint red clumps for the metal-poor and metal-rich populations in the Milky Way bulge
Seungsoo Hong, Dongwook Lim, Young-Wook Lee
We examined the double red clump (RC) observed in the Galactic bulge, interpreted as a difference in distance ("X-shaped bulge scenario") or in chemical composition ("multiple popu…