This article reviews recent developments in tests of fundamental physics using atoms and
molecules, including the subjects of parity violation, searches for permanent electric dipole …

Einstein's general theory of relativity from 1915 1 remains the most successful description of
gravitation. From the 1919 solar eclipse 2 to the observation of gravitational waves 3, the …

The ALPHA experiment has recently entered an expansion phase of its experimental
programme, driven in part by the expected benefits of conducting experiments in the …

The photon—the quantum excitation of the electromagnetic field—is massless but carries
momentum. A photon can therefore exert a force on an object upon collision. Slowing the …

In 1928, Dirac published an equation that combined quantum mechanics and special
relativity. Negative-energy solutions to this equation, rather than being unphysical as initially …

The spectrum of the hydrogen atom has played a central part in fundamental physics over
the past 200 years. Historical examples of its importance include the wavelength …

Antihydrogen atoms with K or sub-K temperature are a powerful tool to precisely probe the
validity of fundamental physics laws and the design of highly sensitive experiments needs …

Charge, parity, and time reversal (CPT) symmetry implies that a particle and its antiparticle
have the same mass. The antiproton-to-electron mass ratio M p¯/me can be precisely …

Our current understanding of the Universe comes, among others, from particle physics and
cosmology. In particle physics an almost perfect symmetry between matter and antimatter …

Antihydrogen, the lightest atom consisting purely of antimatter, is an ideal laboratory to study
the CPT symmetry by comparison with hydrogen. With respect to absolute precision …