4 papers
Some problems associated with the standardization of the light curve of type 1a supernovae
A. P. Mahtessian, G. S. Karapetian, H. F. Khachatryan +4
We show that the parameters used to standardize the luminosity of Type 1a supernovae in the SALT2 and SiFTO models are strongly dependent on the redshift z. Consequently, when stan…
Signatures of Galactic Expansion in Gaia DR3: Implications for the JWST Early-Galaxy Puzzle
G. S. Karapetian, A. P. Mahtessian, L. E. Byzalov +2
Recent observations with the James Webb Space Telescope (JWST) of massive galaxies at ages below 1 Gyr pose a challenge to standard models of galaxy formation, which predict signif…
Evidence of Galactic Center Expansion from Gaia DR3 Stars along the South North Axis: Implications for the JWST Early Galaxy Problem
G. S. Karapetian, L. E. Byzalov, M. A. Hovhannisyan +2
Recent observations with the James Webb Space Telescope (JWST) have revealed massive, evolved galaxies only a few hundred million years after the Big Bang, challenging standard cos…
Study of the motion of Globular Clusters relative to the plane and center of the Galaxy based on Gaia and HST data
G. S. Karapetian, A. P. Mahtessian, M. A. Hovhannisyan +1
The authors of the article set out to investigate the motion of Globular Star Clusters (GCs) of the Milky Way relative to the plane and center of the Galaxy. For this study, we use…