ERC FUNDED PROJECTS

The detection of primordial gravity waves created during the Big Bang ranks among the greatest potential intellectual achievements in modern science. During the last few decades, the instrumental progress necessary to achieve this has been nothing short of breathtaking, and we today are able to measure the microwave sky with better than one-in-a-million precision. However, from the latest ultra-sensitive experiments such as BICEP2 and Planck, it is clear that instrumental sensitivity alone will not be sufficient to make a robust detection of gravitational waves. Contamination in the form of astrophysical radiation from the Milky Way, for instance thermal dust and synchrotron radiation, obscures the cosmological signal by orders of magnitude. Even more critically, though, are second-order interactions between this radiation and the instrument characterization itself that lead to a highly non-linear and complicated problem. I propose a ground-breaking solution to this problem that allows for joint estimation of cosmological parameters, astrophysical components, and instrument specifications. The engine of this method is called Gibbs sampling, which I have already applied extremely successfully to basic CMB component separation. The new and ciritical step is to apply this method to raw time-ordered observations observed directly by the instrument, as opposed to pre-processed frequency maps. While representing a ~100-fold increase in input data volume, this step is unavoidable in order to break through the current foreground-induced systematics floor. I will apply this method to the best currently available and future data sets (WMAP, Planck, SPIDER and LiteBIRD), and thereby derive the world's tightest constraint on the amplitude of inflationary gravitational waves. Additionally, the resulting ancillary science in the form of robust cosmological parameters and astrophysical component maps will represent the state-of-the-art in observational cosmology in years to come.

1 999 205 €

Start date: 2018-04-01, End date: 2023-03-31

Advances in technology and methodology over the last decade, have enabled the study of galaxies to the highest redshifts. This has revolutionized our understanding of the origin and evolution of galaxies. I have played a central role in this revolution, by discovering that at z=2, when the universe was only 3 Gyr old, half of the most massive galaxies were extremely compact and had already completed their star formation. During the last five years I have led a successful group of postdocs and students dedicated to investigating the extreme properties of these galaxies and place them into cosmological context. Combining a series of high profile observational studies published by my group and others, I recently proposed an evolutionary sequence that ties together the most extreme galaxies in the universe, from the most intense dusty starburst at cosmic dawn, through quasars: the brightest sources in the universe, driven by feedback from supermassive black holes, and galaxy cores hosting the densest conglomerations of stellar mass known, to the sleeping giants of the local universe, the giant ellipticals. The proposed research program will explore if such an evolutionary sequence exists, with the ultimate goal of reaching, for the first time, a coherent physical understanding of how the most massive galaxies in the universe formed. While there is a chance the rigorous tests may ultimately reveal the proposed sequence to be too simplistic, a guarantied outcome of the program is a significantly improved understanding of the physical mechanisms that shape galaxies and drive their star formation and quenching

1 999 526 €

Start date: 2015-09-01, End date: 2020-08-31

The detection of life beyond our Solar System is possible only via the remote sensing of the atmospheres of exoplanets. The recent discovery that small exoplanets are common around cool, red stars offers an exciting opportunity to study the atmospheres of Earth-like worlds. Motivated by this revelation, the EXOKLEIN project proposes to construct a holistic climate framework to understand astronomical observations in the context of the atmosphere, geochemistry and biosignatures of the exoplanet. The proposed research is divided into three major themes. Research Theme 1 aims to construct a virtual laboratory of an atmosphere that considers atmospheric dynamics, chemistry and radiation, as well as how they interact. This virtual laboratory enables us to understand the physical and chemical mechanisms involved, as well as predict the observed properties of an exoplanet. Research Theme 2 aims to generalize the carbonate-silicate cycle (also known as the long-term carbon cycle) by considering variations in rock composition, water acidity and atmospheric conditions. The carbonate-silicate cycle is important because it regulates the long-term presence of carbon dioxide (a vital greenhouse gas) in atmospheres. We also aim to investigate the role of the cycle in determining the fates of ocean-dominated exoplanets called “water worlds”. Research Theme 3 aims to investigate the long-term stability of biosignature gases in the context of the climate. Whether a gas uniquely indicates the presence of biology on an exoplanet depends on the atmospheric properties and ultraviolet radiation environment. We investigate three prime candidates for biosignature gases: methyl chloride, dimethylsulfide and ammonia. Overall, the EXOKLEIN project will significantly advance our understanding of whether the environments of rocky exoplanets around red stars are stable and conducive for life, and whether the tell-tale signatures of life may be detected by astronomers.

1 984 729 €

Start date: 2018-02-01, End date: 2023-01-31

The horizon is the line that seems to separate earth from sky, the line that divides all visible categories into two categories: those that intersect the earth’s surface and those that do not. The horizon is key to the experience of space; it defines our perspective on the visible world. The GLOBAL HORIZONS project will investigate the historical meanings and functions of the horizon in visual and intellectual cultures of the pre-Modern world on a global scale. Examining how pre-Modern cultures conceived of the horizon opens a crucial line of inquiry into understanding the many different ways in which humans have conceived of the relationship between an invisible cosmos and the visible world. Non-western art history is rarely taught at European institutions although countless important works of Non-Western art are kept in museum collections all across Europe. Including non-western concepts of pictorial space is key to the project, however, for Eurocentric models of art history have generally privileged the rise of the linear perspective. This framing has limited our understanding of the horizon’s complex rhetorical, visual and epistemological roles. The project’s specific question connects a variety of objects and epistemological categories, such as panel painting, manuscript illumination, profane und religious objects, cartography, travel accounts, and cosmological treaties. The applied methodological approaches will range from art history, visual studies and cultural anthropology. They will also draw upon interdisciplinary expertise, such as technologies of art production, history of science and philosophy. The project thus makes an important contribution to global art history, a highly innovative area in which only very few pre-modern topics have been addressed. It is the ultimate goal of GLOBAL HORIZONS is to suggest a new history of representation in Western medieval art.

1 904 188 €

Start date: 2018-09-01, End date: 2023-08-31