Abstract: I will discuss the problem of time in quantum cosmology and present a possible time evolution for Minisuperspaces.

Abstract:  I will discuss some recent work concerning the existence and properties of zero sound in the Sakai-Sugimoto model at finite
temperature (and large baryon density). After reviewing some background on Landau's Fermi liquid theory and the finite temperature
Sakai-Sugimoto model, I will present new results in this holographic framework, such as spectral functions, quasi normal modes and dispersion relations, and compare them to expectations from Fermi liquid theory and other holographic models.

Abstract: The Level-1 Trigger for the Compact Muon Solenoid (CMS) experiment with an emphasis on the Global Muon Trigger (GMT). I will then detail the planned upgrades to this system for the Large Hadron Collider (LHC) run period beginning in 2015. Finally I will introduce one of the analyses that could significantly benefit from this upgrade.

Abstract: We formulate four-dimensional conformal gravity with (Anti-)de Sitter boundary conditions that are weaker than Starobinsky boundary conditions, allowing for an asymptotically subleading Rindler term concurrent with a recent model for gravity at large distances. We prove the consistency of the variational principle and derive the holographic response functions. One of them is the conformal gravity version of the Brown-York stress tensor, the other is a `partially massless response'. The on-shell action and response functions are finite and do not require holographic renormalization. Finally, we discuss phenomenologically interesting examples, including the most general spherically symmetric solutions and rotating black hole solutions with partially massless hair.

Abstract: Patchy colloids are a model system introduced to model anisotropic interactions in colloidal dispersion. After a brief introduction on the topic, we introduce Inverse Patchy Colloids, and show our study of the phase diagram, which reveals structures similar to the famous viennese sweets.

In the second part, the integral equation approach to the liquid state theory is briefly summarized, and it is shown wie it can be used to avoid time-consuming simulations, and how we are trying to improve it.

Abstract: The chiral magnetic effect (CME) is a highly discussed effect in heavy-ion collisions stating that, in the presence of a magnetic field B, an electric current is generated in the background of topologically nontrivial gluon fields. We present a holographic (AdS/CFT) description of the CME in terms of a fluid-gravity model which is dual to a strongly-coupled plasma with multiple anomalous U(1) currents. In the case of two U(1) charges, one axial and one vector, the CME formally appears as a first-order transport coefficient in the vector current. We will holographically compute this coefficient at strong coupling and compare it with the hydrodynamic result. Finally, we will discuss an anisotropic variant of the model and study a possible dependence of the CME on the elliptic flow coefficient v_2.

Abstract: I will give a short introduction to supersymmetry and explain what we understand by non-relativistic supersymmetry. This will lead to a notion of non-relativistic supergravity which I will use to construct the action of a (super) point-particle. Finally, I will discuss different gaugings of this action to describe a point-particle in backgrounds with different symmetries; from the Galilean point-particle to the Newton--Cartan point-particle.

Abstract: Advances of Synchrotron sources in the last two decades made it possible to expand Dynamic Light Scattering to the X-ray regime. In recent years our group explored the limits of this technique by using it to study diffusion on the atomic scale. This talk will give an introduction to atomic-scale X-ray Photon Correlation Spectroscopy and discuss how coherent X-rays can give a picture of reals space circumventing the phase problem. Selected diffusion mechanisms will be exemplified and compared with experimental data.

Abstract: In condensed matter systems with strong electronic correlations, the familiar picture of a non-interacting electron cloud breaks down. These materials show facinating "emergent" phenomena. However, the breakthrough in treating many of such systems numerically only came in the 1990s with the advent of dynamical mean field theory (DMFT) [1] and related in ab-initio approaches like LDA+DMFT [2].
DMFT is formulated in terms of the one-particle many-body propagator, the Green's function. Its two-particle counterparts, the vertex functions, have remained largely uncharted territory until recently. However, they are interesting from both a physical and a modelling perspective: vertex functions enter as vertex corrections into the system's response functions (such as the spin susceptibility); their divergencies mark bifurcation points of the system [3]; and they are the central ingredient to most diagrammatic extensions of DMFT [4].
Due to their two-particle nature, vertex functions are both huge in size and rich and non-trivial in structure, which makes them difficult to access by numerical methods such as continuous time quantum Monte Carlo (CT-QMC) [5]. We show that only by a deep understanding of the diagrammatics, asymptotics and symmetries, one can overcome these hurdles. We then turn to the moderatly correlated FeAl alloy and use vertex functions to study the formation and screening of local moments in this compound to explain the absence of magnetic order.

References:
 [1] A Georges et al. - Rev. Mod. Phys. 68, 13-125 (1996)
 [2] K Held et al. - J. Phys. Condens. Matter 20 064202 (2008)
 [3] T Schäfer et al. - Phys. Rev. Lett. 110, 246405 (2013)
 [4] e.g., A Toschi et al - Phys. Rev. B 75, 045119 (2007)
 [5] E Gull et al. - Rev. Mod. Phys. 83, 349 (2011)

Abstract: In this talk I will illustrate how to include heavy quark effects in QCD processes with various dynamical scales. The resulting mass factorization theorems resum all large logarithms and can account for arbitrary hierarchies between the mass scale and the kinematic scales. Specific examples covered are the hadronic R-ratio, deep-inelastic scattering and event shapes.

Abstract: Calculating electronic properties of materials is an important task in solid state theory. A powerful tool to perform electronic structure calculations is density functional theory in its local density approximation (LDA). However, LDA fails if electronic correlations are strong. On the other hand, the dynamical mean field theory (DMFT) can deal with strongly correlated model Hamiltonians. In this talk I will explain how LDA and DMFT can be combined in order to perform realistic calculations for strongly correlated materials and I will show some preliminary results for the materials I am currently working on.

Abstract: In the frame of the qBounce experiment, resonant transitions between several of the lowest quantum states of gravitationally bound neutrons are observed for the first time. The coupling between the states is provided by well-defined mechanical oscillations of neutron mirrors. The presented spectroscopy method enables a frequency's view on Newton's Inverse Square Law of Gravity, which has been put under scrutiny by theoretical extensions of the Standard Model. As yet undiscovered particles of dark matter or dark energy would introduce a measurable energy shift, we can present experimental limits for dark-energy chameleons fields and the pseudo-scalar interaction of an axion, a prominent dark matter particle.

Abstract: I outline the various apparently different problems which can be dealt with the symmetries of the Galilean Conformal Algebra. These include applications to flat holography, non-relativistic physics and the tensionless limit of string theory.

Abstract: The use of periodic boundary conditions is a common trick used when doing molecular simulations on the computer. After a short introduction of this technique, we look at the effect it has on the simulation of droplets in a simulation box which is the emergence of so called geometric phases that are characterized by droplet shapes other than spherical. Transitions between these phases have been observed to be responsible for exponential slowing down in simulations[1] and hence we will try characterize them by finding a suitable order parameter.
[1] T. Neuhaus and J. S. Hager, J. Stat. Phys. 113, 47 (2003).

Abstract: In the past 15 years the search for a possible violation of Lorentz invariance has become one pillar in fundamental research. This talk will give an introduction to this hot and fascinating topic. First of all it will be motivated why Lorentz symmetry may be violated in the vicinity of the Planck scale. As a next step an effective framework, which describes Lorentz violation for energies much smaller than the Planck scale, shall be introduced. The latter is known as the Standard-Model Extension whose Lagrange density includes all terms consistent with the ordinary Standard Model (plus gravity) but violating Lorentz invariance. This will lead us to possible phenomena that occur in this context such as vacuum birefringence. The last part of the talk will be dedicated to examples for experiments that are used to search for Lorentz violation in nature.

Abstract: The theoretical description of correlated quantum many-body systems is one of the major challenges in current physics. Quantum correlations occur at practically all levels of complexity: from multi-photon ionization of atoms to high temperature superconductivity in solids. In general, the amount of information stored in the wavefunction makes it inaccessible to analytical or even numerical calculations. However, many dynamical observables including the energy are completely defined by the reduced two-particle density matrix. Recently a method has been developed to calculate the ground state energy of complex molecules based on the two-particle density matrix without knowledge of the full wavefunction. In this talk i will present a time-dependent version of this theory. As a testing ground we use the lithium hydrate molecule in high intense laser fields. The accuracy of the newly developed theory is benchmarked against the multiconfigurational time-dependent Hartree-Fock method.