The Pauli Exclusion Principle (PEP) is a pillar of modern physics: it forbids to two or more fermions to occupy the same quantum state, stabilising matter.  PEP is intimately related to the Spin Statistics theorem, in turn based on the Lorentz invariance, causality and locality principles. Thus PEP is strongly dependent by the microscopic structure and symmetries of space and time. Tiny PEP violations can be induced by quantum gravity effects, providing a possible test channel of theories of the Planck scale physics.

    VIP experiment is based in Gran Sasso National Laboratory. The main aim of VIP is to search for rare atomic transitions forbidden by the Pauli Exclusion Principle. Such transitions are predicted by several quantum gravity models with non-commutative space-time coordinates. Even if extremely suppressed effects, these can be detected, as an amplifier, from high statistical sample collected by VIP detectors.

    In this paper, Andrea Addazi and his collaborators of VIP experiment show that VIP in phase 2 (VIP-2) achieves a world-record bound on Pauli Exclusion Violating processes, in atomic physics, induced by non-commutative space-time quantum gravity. Such a result sets an important milestone towards our comprehension of quantum gravity and the fundamental nature of space and time. In fact several models of non-commutative quantum gravity, including the notorious kappa and theta-Poincaré, are ruled out until energy scales close to the Planck one. These results indicate that such models are not correct ways towards searches of a final theory coherently unifying General Relativity and Quantum Mechanics.

    The results open a new exciting frontier of quantum gravity phenomenology and they motivate an update of the experiment (VIP-3) already approved by INFN as an evolution of the previous VIP apparatus towards deeper explorations of quantum gravity.