Well… The effecrive coupling constant changes with energy. A high energy experiment behaves differently than at lower energies. The coupling constant is above 1 for the strong force at low energies, but there is ‘asymptotic freedom’ which makes it below 1 at high energies. For EM it is always below 1. I would guess they reference a ‘bare’ value here.
The purpose of these graphs are not how they look in our universe though. Rather a common way of doing anthropic style arguments. Without measuring the value of the constants, from the graph we can know from just knowing there are stable carbon and non-relativistic atoms pretty exactly where the values of the constants must be. Similar arguments can be used to pinpoint the cosmological constant from the existance of galaxies.
Well… The effecrive coupling constant changes with energy. A high energy experiment behaves differently than at lower energies. The coupling constant is above 1 for the strong force at low energies, but there is ‘asymptotic freedom’ which makes it below 1 at high energies. For EM it is always below 1. I would guess they reference a ‘bare’ value here.
The purpose of these graphs are not how they look in our universe though. Rather a common way of doing anthropic style arguments. Without measuring the value of the constants, from the graph we can know from just knowing there are stable carbon and non-relativistic atoms pretty exactly where the values of the constants must be. Similar arguments can be used to pinpoint the cosmological constant from the existance of galaxies.