Giovedì 29 giugno alle ore 15:00, il Prof. Joseph Jensen della Utah Valley University, Orem (USA) terrà il seminario dal titolo “Building a Better Ladder“.
The current conflict in cosmology between the locally-measured value of the Hubble constant and that derived from observations of the cosmic microwave background using highly consistent LCDM models points to either significant systematic errors in the distance scale calibration or new physics that goes beyond the current best models. Since the key to unraveling this issue is eliminating as many systematic uncertainties as possible, we are building a new and independent distance ladder based on red giant branch stars to measure H0 without any reliance on Cepheid variable stars and type Ia supernovae, which currently compose the most precise rungs on the distance ladder. The tip of the red giant branch (TRGB) and surface brightness fluctuations (SBF) are the most promising alternatives that can achieve comparable precision. Our team is using new HST and JWST data to build an independent high-precision distance ladder to help find a solution to one of the most important unanswered questions in physics today.