The largest structures in the Universe emerged from the smallest structures resolvable in our laboratories — this insight can be considered one of the biggest triumphs of modern physics. It is reflected in the Helmholtz research programme Matter and the Universe, which addresses many of the most fundamental issues of elementary particle physics, hadronic and nuclear physics and astroparticle physics in a unique and comprehensive way.
Significant strides have been made in understanding, at a fundamental level, how the Universe evolved immediately after the Big Bang at distance scales when all forces supposedly were equal. Once the Universe had sufficiently expanded and the interactions became distinguishable, a description in terms of the Standard Model (SM) of particle physics became possible. This theory and its possible extensions are a main focus of the topic Fundamental Particles and Forces. The model has withstood numerous experimental tests; its most recent triumph was the discovery of
a Higgs boson at a mass of 126 GeV at CERN, which resulted in the award of the 2013 Nobel prize to F. Englert and P. Higgs. Yet the theory is known to be incomplete – new physics has to enter below the Planck scale, where gravity is of a similar strength as the other interactions.
As the Universe cooled down, nucleons were formed from a quark-gluon plasma and the simplest atoms were created. At much lower temperatures and while the Universe was still expanding rapidly, gravity took over and dust condensed into stars, element synthesis began and eventually heavy elements were made in star collapses. The research topic Cosmic Matter in the Laboratory addresses these complex forms of matter and their interactions in hadrons and nuclei.
The standard model of cosmology (ΛCDM) has been successful in describing the features of the Universe. However, the evidence for Dark Matter and for an accelerated expansion of the Universe came as a surprise. There are also many open issues in our understanding of amazing objects such as supernovae or Black Holes in the Universe. We probe the Universe with all available cosmic messenger particles to obtain the complementary information that is needed to get the complete picture. Astroparticle physics, at the intersections of astronomy, astrophysics, cosmology and particle & nuclear physics, is the subject of research in the topic Matter and Radiation from the Universe.
This proposal presents a research strategy towards a consistent and complete theoretical description of the topics sketched above. The vision for the Helmholtz programme Matter and the Universe is to contribute significantly to this endeavour. By its very nature our research requires large instruments like particle accelerators, complex detectors, sensitive observatories in remote locations and powerful IT infrastructures. In Germany, the Helmholtz Association develops, builds and operates such facilities and conducts leading-edge research.
The challenges for Matter and the Universe include the development, construction and operation of large-scale infrastructures. This is part of the Helmholtz mission, which is stated at the very beginning of this document. It is essential for the success of the programme that we have the right instruments to perform cutting-edge research. As a consequence the research infrastructures must continuously evolve driven by the needs of science.
The primary focus of Matter and the Universe is basic research for advancing our knowledge, understanding and conception of the world. It is worth emphasizing that basic science has an enormous societal relevance and a deep long-term impact, especially for three significant sectors, (i) public awareness, (ii) education and (iii) innovation, see here.
Achieving a better understanding of the smallest, the most complex and the largest constituents and features of the Universe is not a small task. The joint competences of Helmholtz scientists working on elementary particle physics, hadron and nuclear physics, and astroparticle physics in one programme provide a powerful approach that is matched by few on the worldwide level.