Kolloquien

No experiment today provides evidence that gravity requires a quantum description. The growing ability to achieve quantum optical control over massive solid-state objects may change that situation – by enabling experiments that directly probe the phenomenology of quantum states of gravitational source masses. I will review the current status in the lab and the challenges to be overcome for future experiments.   mehr...

“Climate change is physics”, as the 2021 Nobel Prize in Physics has highlighted to the broader public. A hierarchy of physically based models of the atmosphere and ocean, which have been developed since the mid 1960s, has predicted fingerprints of climate change that we now observe worldwide.   mehr...

The large-scale structure of our Universe is seen as a result of quantum field fluctuations amplified by the evolution of space-time itself. Quantum fields in curved spacetimes have many tantalizing theoretical properties, for example particles are being produced by the time-dependence of the geometry.   mehr...

The richness and diversity of planetary systems that have now been detected have modified our perspective on planet formation and our place in the Universe. They also represent an historical opportunity of perspectives and a compelling call to look for signs of life on these new worlds and to reflect on the origin of life in the Solar System.   mehr...

Ever noticed that annoying lag that sometimes happens during the internet streaming from, say, your favorite football game? Called latency, this brief delay between a camera capturing an event and the event being shown to viewers is surely annoying during the decisive goal at a World Cup final. But it could be deadly for a passenger of a self-driving car that detects an object on the road ahead and sends images to the cloud for processing.   mehr...

In the last decades, gravity experiments have been experiencing a renaissance for several reasons: Modern astronomical observations clearly point to the existence of Dark Energy and Dark Matter. Their true nature and content remain a mystery however. Furthermore, prominent candidates to formulate a consistent quantum theory of gravitation require extra spatial dimensions.   mehr...

Exotic worlds were hiding under the Antarctic ice for millions of years. A specialized seafloor drill rig finally enabled to recover those enigmatic sediments, witnessing lush and warm climate conditions near the South Pole – unexpected for those highest latitudes with more than four months of polar night darkness. This knowledge changed our view of the severity of global climate conditions during phases of peak global warmth and reveal the significance modern ice-sheet presence has for buffering future climate runaway.   mehr...

Mankind has underestimated the lever it has in changing the biogeochemical state of the planet earth by emitting greenhouse gasses. We are in a position where the state of the planet is about to change into a condition that may be detrimental for mankind. It is thus extremely urgent to minimize the emission of greenhouse gasses in a global dimension. This can be achieved if the existing world market of fossil energy is replaced by a world market of renewable energies. Even so it is a challenging task and requires rebuilding the largest industry on earth within one generation.   mehr...

Biological systems avoid equilibrium by taking chemical energy from their surroundings and using it to do work. Cells organise intra-cellular components into the structures that allow them to grow, reproduce and move. Tissues, collections of cells, differentiate locally as they develop to perform the complex functions of different organs.   mehr...

Particle physics is engaged in a worldwide effort to deepen our understanding of key issues, from the origin of dark matter and neutrino masses, to the dynamics of electroweak symmetry breaking and of non-perturbative strong interactions. A wide landscape of facilities and experiments, in the laboratory, in the sky and underground, in addition to theoretical work, are mobilized in these efforts. In this landscape, collider experiments play a special role, and, with the current success of the LHC, are consolidating their unique potential to continue driving the future progress.   mehr...

The field of Asteroseismology — the study of the internal structures of stars through their global intrinsic oscillations, has been revolutionised over the past decade. This revolution was possible thanks to the high-precision high-cadence photometric data from space missions CoRoT, Kepler, K2 and TESS. These missions provided long timeseries data for hundreds of thousand stars. In many cases the brightness variations in these timeseries data reveal the intrinsic eigenmodes of the stars. These eigenmodes are defined by the internal structure of the star and hence, the stellar structure can be derived from the frequencies of the eigenmodes.   mehr...

About 15 years ago, it was realized that Random Tensors exhibit a 1/N expansion dominated by melonic graphs. This result was the foundation of the theory of random tensors. In this talk, I will present this 1/N expansion and its implications for the study of random geometries and strongly interacting quantum field theories.   mehr...

A central challenge for animals when alone, or when grouping with others, is deciding where to go. Running, swimming, or flying through the world, animals are constantly making decisions while on the move—decisions that allow them to choose where to eat, where to hide, and with whom to associate. Despite this, most studies have considered only on the outcome of, and time taken to make, decisions.   mehr...