Dark energy at early times, the Hubble parameter, and the string axiverse
Dark energy at early times, the Hubble parameter, and the string axiverse
Precise measurements of the cosmic microwave background (CMB) power spectrum are in excellent agreement with the predictions of the standard $\Lambda$CDM cosmological model. However, there is some tension between the value of the Hubble parameter $H_0$ inferred from the CMB and that inferred from observations of the Universe at lower …