Objective The structure of relativistic quantum vacuum (RQV) in our Universe is one of the main challenges in modern physics. We plan to advance our understanding of the vacuum structure and on this basis treat the most important unsolved problems in physics, such as the cosmological constant problem (why the measured vacuum energy is 120 orders of magnitude smaller than estimates from the zero point motion) and the hierarchy problem (why the masses of the known particles in the Standard Model (SM) of particle physics are much smaller than the Planck energy). The quantum vacuum shares many common properties with topological matter. The goal of the proposal is to concentrate both theoretical and experimental efforts in the investigation of connections between the topological quantum matter and RQV, to enhance understanding of topological condensed-matter systems especially in the ultra-low-temperature regime, and to apply this experience to solution of problems in SM & cosmology. As a condensed-matter system we shall use superfluid phases of liquid 3He – unique topological materials, which are the most close to SM and gravity: Superfluid 3He-A, where the low-energy excitations are topologically protected Weyl fermions, gauge bosons, and gravitons, is similar to the vacuum of SM above the electroweak transition. The fully gapped topological superfluid 3He-B with its Higgs bosons is the counterpart of SM vacuum in its broken symmetry phase. In particular, theory of relaxation of dark energy will be accompanied by experimental study of resonant decay of coherent states of non-equilibrium superfluid vacuum. Determination of the topological classes of the quantum vacua of SM including the vacua with Majorana fermions will be accompanied by experimental studies of Majorana fermions on the boundaries of topological superfluids and in cores of quantized vortices. Theory of extra Higgs bosons in SM will be accompanied by experimental study of light and heavy Higgs modes in 3He-B. Fields of science natural sciencesphysical sciencestheoretical physicsparticle physicsfermionsnatural sciencesphysical sciencesquantum physicsquantum field theorynatural sciencesphysical sciencesastronomyastrophysicsdark matternatural sciencesphysical sciencesastronomyphysical cosmologynatural sciencesphysical sciencestheoretical physicsparticle physicshiggs bosons Keywords topological matter superfluid 3He Majorana fermions relativistic quantum vacuum cosmological constant Programme(s) H2020-EU.1.1. - EXCELLENT SCIENCE - European Research Council (ERC) Main Programme Topic(s) ERC-ADG-2015 - ERC Advanced Grant Call for proposal ERC-2015-AdG See other projects for this call Funding Scheme ERC-ADG - Advanced Grant Host institution AALTO KORKEAKOULUSAATIO SR Net EU contribution € 2 159 191,00 Address OTAKAARI 1 02150 Espoo Finland See on map Region Manner-Suomi Helsinki-Uusimaa Helsinki-Uusimaa Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 2 159 191,00 Beneficiaries (1) Sort alphabetically Sort by Net EU contribution Expand all Collapse all AALTO KORKEAKOULUSAATIO SR Finland Net EU contribution € 2 159 191,00 Address OTAKAARI 1 02150 Espoo See on map Region Manner-Suomi Helsinki-Uusimaa Helsinki-Uusimaa Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 2 159 191,00