PIRSA:21020006

Video URL

https://pirsa.org/21020006

Tension in the Hubble Constant: Is There a Crisis in Cosmology?

Freedman, W. (2021). Tension in the Hubble Constant: Is There a Crisis in Cosmology?. Perimeter Institute for Theoretical Physics. https://pirsa.org/21020006

Freedman, Wendy. Tension in the Hubble Constant: Is There a Crisis in Cosmology?. Perimeter Institute for Theoretical Physics, Feb. 24, 2021, https://pirsa.org/21020006 

          @misc{ scivideos_PIRSA:21020006,
            doi = {10.48660/21020006},
            url = {https://pirsa.org/21020006},
            author = {Freedman, Wendy},
            keywords = {Other Physics},
            language = {en},
            title = {Tension in  the Hubble Constant: Is There a Crisis in Cosmology?},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2021},
            month = {feb},
            note = {PIRSA:21020006 see, \url{https://scivideos.org/pirsa/21020006}}
          }

Wendy Freedman University of Chicago

Talk numberPIRSA:21020006
DOI10.48660/21020006
Source RepositoryPIRSA
Collection
Talk Type Scientific Series
Subject

Abstract

An important and unresolved question in cosmology today is whether there is new physics that is missing from our current standard Lambda Cold Dark Matter (LCDM) model. A current discrepancy in the measurement of the Hubble constant could be signaling a new physical property of the universe or, more mundanely, unrecognized measurement uncertainties. I will discuss two of our most precise methods for measuring distances in the local universe: Cepheids and the Tip of the Red Giant Branch (TRGB). I will present new results from the Carnegie-Chicago Hubble Program (CCHP), the goal of which is to independently measure a value of the Hubble constant to a precision and accuracy of 2%. Using the Hubble Space Telescope Advanced Camera for Surveys,  we are  using the TRGB to calibrate Type Ia supernovae. I will  address the uncertainties,  discuss the current tension in Ho, and whether there is need for additional physics beyond the standard LCDM model.