Kolloquien

Heliophysics encompasses research of phenomena as diverse as dynamo processes in the solar interior, solar eruptions, the interaction of solar particles and field with the Earth’s magnetic field, and the aurora. These processes and interactions are largely of plasma physical nature. Heliophysics systems range from cold, collisional plasmas, to hot, collisionless, and even relativistic scenarios, the dynamics of many of which are still not or only poorly understood.   mehr...

Currently, the work of finding a theory of quantum gravity is as much a struggle to find the right concepts on which to base the theory, as a struggle to do technical calculations correctly.   mehr...

Man-made emissions of the greenhouse gases carbon dioxide and methane are the main drivers of climate change. The two gases also play a key role in climate feedbacks since their atmospheric abundances are regulated by the carbon cycle which itself is sensitive to climate. Measuring concentration gradients of the greenhouse gases in the Earth's atmosphere can, in principle, inform on both, the man-made emissions and the biogeochemical processes by which the world's ecosystems remove anthropogenic carbon from the atmosphere.   mehr...

Über Elektromobilität wird in Deutschland viel geredet, aber passiert ist bisher scheinbar wenig. Tatsächlich hat sich jedoch in den letzten Jahren ganz viel getan. Die Lade-Infrastruktur wurde erheblich ausgebaut. Moderne Batterien und elektrische Antriebe sind viel leistungsfähiger und auch umweltfreundlicher geworden und nun kommen auch bezahlbare Elektroautos auf den Markt.   mehr...

Regulating the emergence of leading individuals is a central problem to collectively migrating biological entities. For example, leaders in the mobile animal groups arise through collective decision making of the followers. However, the fundamental control of leader selection remains unclear in the physiologically relevant collective migration of epithelial cells.   mehr...

Why are we brushing our teeth? To remove the formed biofilm and to prevent tooth decay. But why is the biofilm so sticky, which forces are involved? To answer theseand other questions, we teamed up with colleagues in microbiology and clinical dentistry to identify suitable model systems for the investigation and quantification of the forces involved.   mehr...

Because of the complex interdependence of physics and mathematics their relation is not free of tensions. The talk looks at how the tension has been perceived and articulated by some physicists, mathematicians and mathematical physicists.   mehr...

What is known as the “many-body problem” is the simple fact that our theoretical toolbox is generally incapable of handling systems containing many mutually interacting quantum particles. In one dimension, there exist however special theories for which exact solutions of the Schrödinger equation can be found. Long viewed as exceptional artifacts or irrelevant curiosities, these “integrable systems" have now come to play a major role in our understanding of quantum statistical mechanics and strongly-correlated systems.   mehr...

Supercooled liquids – liquids that are metastable with respect to the crystalline form – represent an important class of out-of-equilibrium systems whose study is related to a number of fundamental questions in statistical and condensed matter physics. Water represents one prominent example that highlights the relevance of supercooled liquids. Water’s behavior is unusual with respect to that of most other liquids, and it was long speculated that clues about this anomalous behavior might be found at temperatures well below the melting point.   mehr...

In 1952, Erwin Schrödinger wrote in The British Journal for the Philosophy of Science:
“One never realizes experiments with a single electron or an atom or a small molecule. In thought experiments, one assumes that sometimes this is possible; invariably, this leads to ridiculous consequences... One may say that one does not realize experiments with single particles, more than one raises ichthyosaurs in the zoo.”   mehr...

LHCb is one of the four large experiments located at the Large Hadron Collider close toGeneva, studying pp collisions at centre-of-mass energies up to 13 TeV. The LHCb physics programme is focused on performing precision measurements in the bottom and charm system. Loop dominated processes are an excellent laboratory to search for signs of potential new particles and interactions. The talk will give an introduction to the concepts of flavour physics, present a selected overview of recent physics highlights and report on the challenges for the currently ongoing upgrade of the LHCb experiment.   mehr...

The endeavour of quantum electronics is driven by one of the most ambitious technological goals of today’s scientists: the realization of an operational quantum computer. We start to address this goal by the new research field of molecular quantum spintronics, which combines the concepts of spintronics, molecular electronics and quantum computing. The building blocks are magnetic molecules, i.e. well-defined spin qubits.   mehr...

Dipolar interactions are fundamentally different from the usual van der Waals forces in real gases. Besides the anisotropy the dipolar interaction is nonlocal and as such allows for self organized structure formation. In 2005 the first dipolar effects in a quantum gas were observed in an ultracold Chromium gas. By the use of a Feshbach resonance a purely dipolar quantum gas was observed three years after.   mehr...