Author Date

2025-05-21

Degree Name

Department

Physics and Astronomy

College

Physical and Mathematical Sciences

Defense Date

2025-05-08

Publication Date

2025-07-28

First Faculty Advisor

Christopher Verhaaren

First Faculty Reader

Benjamin Boizelle

Honors Coordinator

Karine Chesnel

Keywords

cosmology, Hubble, SH0ES, Planck

Abstract

Early universe measurements of the Hubble constant usually find the best-fit value for H₀ given a specific data set and a particular cosmological model. Planck’s all-sky survey of the Cosmic Microwave Background is a common choice for this data, and is often supplemented with additional constraints from other measurements of cosmological phenomena. For example, the SH0ES collaboration’s measurement of H₀ from local type Ia supernovae is a common constraint to include, in the hope of reconciling the tension between late and early universe measurements. We attempt to quantify the effect of this constraint on early universe measurements of H₀. We obtain values for H₀ from several cosmological models—ΛCDM, CPL dark energy, and exponential acoustic dark energy—under two sets of constraints: only CMB data, and CMB data as well as the SH0ES measurement. We compare these results to each other and find that, for these models, constraining the H₀ measurement with SH0ES’ measurement generally reduces the Hubble tension by ~0.5σ. Given the limited scope of this study, our results are probably not generalizable to models other than the ones we examined.