IAU01763
Presentation type requested: EITHER
A PROBLEM IN THE HUBBLE CONSTANT FROM GRAVITATIONAL LENSING
Masamune Oguri
Department of Physics, University of Tokyo
Gravitational lensing is known to be a powerful tool to determine the Hubble constant directly without using the distance ladder. But the derived values of the Hubble constant tends to be significantly smaller compared with those derived from other methods. The situation is, however, somewhat complicated because of the degeneracy between radial mass distribution of the lens galaxy and the Hubble constant: By assuming more centrally concentrated mass distribution one can reconcile the Hubble constant from gravitational lensing with that from other methods, although such concentrated mass distribution may conflict with cold dark matter scenario. We show that gravitational lensing of distant supernovae breaks this degeneracy and allows one to estimate the Hubble constant accurately. We also discuss possible reasons why values of the Hubble constant from gravitational lensing are so small.
IAU XXV General Assembly | IAU216 HOME PAGE | IAU216 Speaker Program | IAU216 Poster Program