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Speaker: Taylor Hoyt (LBNL) – Title: Toward a Precision Cosmology Measurement of the Hubble Constant
November 7 @ 4:00 pm - 5:00 pm
Research Progress Meeting
Date: November 7, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Taylor Hoyt (LBNL)
Title: Toward a Precision Cosmology Measurement of the Hubble Constant
Abstract: The local value of the Hubble constant (H0) derived from a Cepheid calibration of nearby supernovae (SNe) continues to disagree with values derived from a Lambda(or w)CDM interpretation of large scale cosmological datasets from, e.g., Planck or DESI. The Cepheid-SN and high-z values of H0 consistently come in close to 73 and 68 km/s/Mpc, respectively, with a latest claim that the Hubble tension has surpassed 5 sigma significance. At the same time, a calibration of the SNe based on the Tip of the Red Giant Branch (TRGB) distance indicator suggests significantly less of a tension, consistently returning values near 69.5 km/s/Mpc. This persistent local Hubble Tension indicates that classical H0 experiments have not yet reached the level of accuracy required of a “precision cosmology” measurement.
To this end, I will discuss ongoing efforts aimed at evaluating, and ultimately reducing, the amount that underestimated systematic errors could contribute to SN-derived H0 measurements and subsequently bias the evidence for or against the Hubble Tension. These efforts include: new, higher signal-to-noise distance measurements from JWST, investigations into the differing treatment of nearby SNe, and the calibration of a new methodology for SN distance measurement twice as precise and accurate as the canonical approach. These paths together will ensure a more complete understanding of the Hubble Tension, its significance (e.g., H0 tails), and will prove crucial in ushering the accuracy of local H0 measurements into the regime of precision cosmology.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=K2tKUm1VZjRlV1J5RHE3cXdHQzRxdz09
Meeting ID: 988 5432 2464
Passcode: 142239