Abstract: Quantum forces are long-range interactions arising from quantum fluctuations of light mediator fields—either fermionic or bosonic—that couple feebly to matter. Despite their weakness, such forces can leave observable imprints in the early universe and in precision measurements. In this talk, I will discuss quantum forces both within the Standard Model and in the dark sector.
First, the Standard Model predicts a unique quantum force mediated by the exchange of two neutrinos. Although extremely weak, this "neutrino force" can manifest in atomic systems and in backgrounds of cosmic, solar, or reactor neutrinos. I will present our recent progress in probing this effect and show that its magnitude in atoms may have important implications for precision measurements, including determinations of the Weinberg angle at low energies.
Next, I will turn to quantum forces beyond the Standard Model. In the perturbative regime, I will discuss axion-mediated quantum forces and their implications for axion detection experiments. In the nonperturbative regime, I will show how such forces lead to Sommerfeld enhancement and discuss the resulting impact on dark matter evolution and cosmology.