Copenhagen-Asia-America Network for Dark cosmologY – University of Copenhagen

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Copenhagen-Asia-America Network for Dark cosmologY

The Pinwheel Galaxy. Credit: X-ray: NASA/CXC/SAO; IR & UV: NASA/JPL-Caltech; Optical: NASA/STScI


The Dark Cosmology Centre has received support from the Danish Agency for Science Techonolgy and Innovation and the Niels Bohr International Academy to establish in 2013 the network, Copenhagen-Asia-America Network for Dark cosmologY

The participants of CAANDY will study the topics in cosmology of most interest to the scientific community today: dark matter, dark energy, inflation and gravity.

August 2012 Kick-off Workshop

The first phase of CAANDY is a one-week workshop with all the members of the network. The aim is to gather scientists at the forefront of cosmology and identify collaborative projects.  We will have one seminar a day by each of the CAANDY representatives that will be focused on describing not the finished, but rather the on-going projects of their groups. Immediately after, these talks will inspire long, all-hands discussion sessions in which we will brainstorm on possible projects to be initiated by CAANDY members.

Once initial projects are found, we will plan and timeline them during work sessions, which will be scheduled along the week. We expect that at the end of the workshop, a number of new projects between local and visiting members will be started.

The purpose of the second phase of CAANDY is to develop these start-up projects and consolidate them through follow-up research stays at the various hubs of the network. After this phase, not only a series of cutting-edge works should be ready for publication in international, peer-reviewed journals, but also strong links between DARK in Denmark and the other leading institutions in Asia and U.S. promise new collaborations in the future as well as continuous visiting programs for researchers in these centres, and in particular for PhD students and postdocs.

Scientific background

The CAANDY network will collaborate on the frontier of the current knowledge in cosmology and physics. The study of how the Universe was born and grew is fundamental science that for first time in human history is becoming available to us thanks to recent revolutionary astrophysical observations. After the discovery of the cosmic microwave background, which consists of a universal bath of ancient photons carrying out a wealth of information from the early universe, and of the late-time cosmic acceleration, using data from far away exploding stars known as supernovae, we are now in the process to use these and many other astrophysical data sets from galaxy clusters, the distribution of galaxies, etc. to better understand the physics underlying the birth of our universe, its evolution over cosmic times, the properties of its various energy components and the expansion of space-time itself.

The current cosmological model matches surprisingly well the astrophysical observations available so far. However, the simplest version of this model is based on assumptions that are yet to be tested precisely. For example, one of these assumptions is that the distribution of density perturbations in the very early universe is essentially random, that is Gaussian. These initial, tiny perturbations grow under gravity and become the large cosmic structures that we observed today (galaxies, clusters of galaxies, super-clusters, voids, etc.). Testing the non-Gaussianitiy of the initial perturbations using early-universe photon (cosmic microwave background) and large scale structure data from satellite missions and ground-based telescopes is of utmost importance to gain insights into the processes occurring during inflation at the very beginning of the Universe. Probing gravity at cosmic scales is also crucial. Einstein’s theory of gravity, General Relativity, is at the core of modern cosmology. Departures from it could explain, e.g., the unexpected late-time acceleration of the cosmic expansion. These measurements, made only over a decade ago, merited the 2011 Physics Nobel Prize. The standard model explains them by assuming a new energy component, dark energy, which takes ~70% of the cosmic budget. Another ~25% is dark matter, a component that, up to now and despite all current efforts, has only revealed itself through its gravitational effects, while the remaining ~5% is normal matter (that is, the cosmic structures discussed above).