The Bonn-Cologne Graduate School of Physics and Astronomy is organizing a weekend seminar at the Physikzentrum Bad Honnef. As in the previous events we will have a mixture of workshops, evening talks, excursions, etc.
There is no fee, but you will be required to pay your own drinks, and you will also need to cover your travel costs. Lodging will be paid, and as there are evening events it is advisable to stay overnight in the Physikzentrum. We are limited to 90 participants, so early registration is recommended.
Date & Venue
Friday, May 19th to sunday, May 21st 2017 at the Physikzentrum Bad Honnef
Deadline for registration is April 31st, 2017.
For registration please use our form. In case of problems, please contact us by e-mail. During the registration you are asked to select workshops out of each slot. Please select something that is NOT in your field of expertise, as the workshops are intended for non-specialists.
Here is a sketch of the program, and a list of the available topics below. Click here for a pdf version
[A2] T. Bollenbach, , Cologne:
[B2] tba, Astro:
[C2] P. Reiter, Cologne:
[A3] H. Meyer, Bonn:
[B3] T. Reiprich, AIFA, Bonn:
[C3S. Förste, Bonn:
|12:00||12:30 Lunch|| |
15:45 Welcome Note
[E1] Schloss Drachenburg (guided tour, entrance fee!) + Drachenfels (hiking)[E2] Löwenburg/Drachenfels (hiking; note that you get the best view of Rhine valley and Siebengebirge from the Löwenburg!)
[E3] Linz by ship (transport fee)
[A1]´S. Diehl, ITP, Cologne:
[B1] S. Walch, , Cologne:
[C1] B.Kubis, HISKP, Bonn:
Prasanna Mukund Bhogale, U Cologne
Data Science & Machine Learning
Dirk Witthaut, FZ Jülich
From time series analysis to the operation of renewable energy systems
|Friday, 19th||Saturday, 20th||Sunday, 21st|
A1: S. Diehl
Recent experimental developments in diverse areas, ranging from cold atomic gases to light driven semiconductors to microcavity arrays, move systems into the focus which are located on the interface of quantum optics, many-body physics and statistical mechanics. They share in common that coherent and driven-dissipative quantum dynamics occur on an equal footing, creating genuine non-equilibrium scenarios without immediate counterpart in equilibrium condensed matter physics.
In this lecture, we will gently introduce a field theory approach to such systems, and make precise in which way these systems qualify as "non-equilibrium" on a microscopic level. We will then show how these microscopic driving conditions translate into macroscopically observable effects ruled out at equilibrium. This will be based on a surprising formal connection of such systems to phenomena like fire spreading and bacterial colony growth.
A2: T. Bollenbach, A. Angermayr
I will give an introduction into several current topics in the fields of biological physics and systems biology. I will focus on recent experimental and theoretical work on bacteria, starting with the topic of antibiotic resistance evolution. Antibiotic resistance is an increasingly serious concern. At the same time, this phenomenon provides a rare opportunity to observe evolution in real time in the laboratory. The most challenging open questions in this field include how key aspects of drug resistance evolution can be predicted and how this worrying process can be slowed down or perhaps even entirely circumvented. Physicists have recently played a central role in tackling this problem by developing new quantitative experimental techniques and theoretical concepts.
A3: H. Meyer
Quantum networks open new possibilities such as inherently secure communication or distributed quantum computing. A quantum network consist of several localized - so called ‘stationary’ quantum bits (qubits), which are interconnected by so called ‘flying’ qubits.
Trapped atomic qubits have outstanding coherence properties of their internal quantum states as they are strongly decoupled from the environment and are therefore excellently suited as stationary qubits in such a network. Due to their electric dipole moment, they also couple to optical photons, which can be used as flying qubits in order to bridge long distances using optical fiber technology.
In my talk I will present trapped atomic ions as stationary qubits for quantum networks. We will discuss how ion trapping works and how different ion trap geometries can be experimentally realized. Also we will talk about how ionic qubits can be coherently controlled using microwave and coherent laser radiation. In order increase the coupling between the atomic states and single optical photons, we will make use of cavity quantum-electrodynamics (cavity-QED) and see how optical resonators can be used in order to efficiently create single photons from a trapped ion system. Finally, we shall see how these photons can be used in order to entangle remote ions and therefore how to realize a quantum network.
B1: S. Walch
Molecular clouds (MCs) condense out of the warm interstellar medium (ISM) on scales of several 100 pc and host filamentary substructures on sub-pc scales. They consist of molecular hydrogen (H2 ), which can only be traced indirectly in observations, and are subject to supersonic turbulence. In the SILCC project, we investigate how a multi-phase interstellar medium (ISM) is shaped and stirred by feedback from massive stars. We compare the impact of the explosion sites of Supernovae, and find that a significant fraction needs to explode in low density environments in order to develop an ISM that is in agreement with observations of the Milky Way. Furthermore, we include star
cluster formation using sink particles, as well as the massive star feedback from these clusters in the form of ionizing radiation and stellar winds. With these simulations we can show that the early feedback by massive stars limits the accretion of fresh gas, i.e. the growth of the star-forming MCs, and thus regulates the overall star formation efficiency. Further, ionizing radiation changes the phase distribution of the ISM as it destroys H2 in favour of atomic hydrogen.
In this contribution I will give an overview of the numerical techniques and physics modeled in these simulations, including magneto-hydrodynamics, radiative transfer, self-gravity, and gas chemistry. In addition, we generate synthetic observations (i) to test the 3D simulations against observations and (ii) to help interpret the observational data. We will report on the techniques to carry out these studies and show some recent results.
B2: tba, Astro
B3: T. Reiprich, M. Ramos-Ceja, J. Hampel
Basically all astronomical objects can be observed in X-rays, including comets, (extrasolar) planets, stars, white dwarfs, neutron stars, black hole surroundings, galaxies, and galaxy clusters. However, their X-ray appearance often differs dramatically to what is seen in visible light. In this overview talk, a broad range of Galactic and extragalactic X-ray observations will be reviewed as well as the most important X-ray emission processes, mirrors, detectors, and satellites. Also, current and expected future X-ray constraints on dark matter and dark energy will be described. Some short more in-depth discussions about galaxy clusters, stars disrupted by supermassive black holes, as well as the upcoming eROSITA space telescope will be provided. The goal of the talk is that students acquire a good, mostly qualitative but comprehensive overview of the X-ray Universe. Basically no astrophysical knowledge is required, some very basic radiation physics background may be helpful.
C1: B. Kubis
Hadron physics is the part of the Standard Model of particle physics that deals with the strong interactions - the bound states made of quarks and gluons. As the strong interactions (in its fundamental form, as derived from the theory named Quantum Chromodynamics) defy the methods of perturbation theory, we still nowadays face a lot of challenges in understanding it sufficiently accurately. In particular, for many searches for physics beyond the Standard Model in high-precision, low-to-moderate energy experiments, the strong interactions pose the major stumbling block. In this presentation, we will give a basic introduction to some of the modern techniques with which we try to solve these problems; as well as discuss a few concrete applications that we are currently working on.
C2: P. Reiter, M. Spieker, S. Pickston
The strong interaction described by quantum chromodynamics is responsible for binding neutrons and protons into nuclei and for the many facets of nuclear structure physics. Combined with the electroweak interaction, it determines the properties of all nuclei in a similar way as quantum electrodynamics shapes the periodic table of elements. In order to understand how the nuclear chart emerges from the underlying strong interactions, the development of a unified description of all nuclei is needed. These developments are closely connected to experimental endeavours with stable and radioactive ion beam facilities to study the structure of exotic nuclei. The study of excited nuclear states is vital in revealing the role played by the strong interaction in atomic nuclei and in understanding nuclear structure phenomena. Ongoing experimental advances in Europe are based on new accelerators facilities and their instrumentation like the FAIR facility at Darmstadt and HIE-ISOLDE at CERN. Examples of recent developments and new measurements will be given emphasizing the role of the Institute of Nuclear Physics at University of Cologne. Moreover, stable beam facilities like the Cologne tandem accelerator will continue to play a vital role in the study of nuclei with programs devoted to high-energetic excitation modes or nuclear astrophysics. In addition, nuclear physics provides important applications like imaging methods in medicine or accelerator mass spectroscopy for dating methods in a multitude of different fields.
C3: S. Förste, A. Gerhardus, T. Schimannek, C. Fierro Cota, U. Ninad and R. Safari
We will provide a non-technical introduction to String theory with an emphasis on non-phenomenological motivation. This will be followed by a lightning tour of the various mathematical research programs that have been fueled by stringy insights. An overview of quantum field theory in curved space-time and black hole thermodynamics then sets the stage for a guided tour on recent ideas about holography.
In this talk we will unpack the commonly used terms *data science* and *machine learning* and attempt to give some flavour of what they mean out in the wilderness outside academia. We will first look at why data science has become so important recently and then introduce a basic data science workflow. Approaching machine learning in this context, we will define a simple framework into which all machine learning algorithms fit and use that to understand how machine learning can be used to solve a real world problem. We will end the talk with a quick overview of the various domains of application for this field and some recent advances.
Saturday Evening: Dirk Witthaut
The mitigation of climate change requires a comprehensive reconstruction of our energy system. Conventional power plants have to be replaced by renewable power sources, in particular wind and solar power. However, the large temporal fluctuations of the generation constitute a major challenge for the operation and security of the electric power system. In my talk I will give a review of the challenges of renewable power fluctuations and highlight the connection to problems in nonlinear dynamics and statistical physics.