Testing Fundamental Physics with Solar Twin Stars

ABSTRACT

The Standard Model of nature's laws cannot explain fundamental constants, like electromagnetism's strength, alpha. Therefore, searches for variations in alpha are key tests of new physics. I will first review the recent progress in quasar absorption line searches for cosmological variations in alpha. Using twins of our Sun – a new probe that unlocks a 1000-fold sensitivity gain – we aim to test alpha's constancy across our Galaxy in a new project. By discovering distant solar twins, we will probe alpha in regions of very different Dark Matter density, which opens an unexplored discovery space. Utilising new and existing high-precision instruments at the European Southern Observatory, we expect to make the most precise astronomical measurement of a fundamental constant, and obtain the first test of variations in alpha across our Galaxy's Dark Matter field.