Fundamental physics constraints from testing the stability of the fine-structure constant with the ELTs

Understand

The increased collecting area of the ELTs will bring fainter high-z targets within the reach of high-resolution ultra-stable spectrographs, thus enabling a new generation of precision consistency tests, including tests of the stability of nature's fundamental couplings.

• For example, the stability of the fine-structure constant can be tested by looking at metal absorption lines produced by the intervening clouds along the line of sight of distant quasars.
• In this contribution, we discuss the performance that can be expected from the ELTs in testing the stability of the fine-structure constant, based on the early ESPRESSO observations, and some comparative forecasts of the impact of these measurements for representative models of fundamental physics and cosmology.