I will explain the physics behind the famous Riemann hypothesis. In particular, I will deconstruct my recent work done in collaboration with Yang-Hui He of Oxford, UK and Vishnu Jejjala of IHES, France (arxiv:0903.4321[math-ph]). The emphasis will be placed on the Hilbert-Polya approach (i.e. trying to find a physical system with eigenvalues given by the Riemann zeros) and the crucial role played by the physics of quantum chaos, as originally pointed out by Michael Berry. Finally, I will outline what role a ``chaotic Riemann string theory'' is expected to play in connection with our recent results.

I will discuss the possibility to use a high energy neutrino beam from a muon storage ring to provide one way communication with a submerged submarine. Neutrino interactions produce muons which can be detected either, directly when they pass through the submarine or by their emission of Cerenkov light in sea water, which, in turn, can be exploited with sensitive photo detectors. Due to the very high neutrino flux from a muon storage ring, it is sufficient to mount either detection system directly onto the hull of the submersible. The achievable data transfer rates compare favorable with existing technologies and do allow for a communication at the usual speed and depth of submarines.

- postponed until the spring semester.

Over the last years, gauge/string duality has been extended to include gauge theories with an arbitrary number of flavors. We study the flavoring procedure in the light of calibrated geometry and discuss the special case of a type IIA dual of N=1 super Yang-Mills with flavors. Relating our results to the standard type IIA/M-theory duality, we find that the usual oxidation formulas cannot accommodate for the additional flavor branes. We address and solve this issue by considering M-theory with torsion, which allows us to construct source-modified equations of motion for eleven-dimensional supergravity.

The NuTeV collaboration extracted a value for the Weinberg angle that has a 3-sigma discrepancy with the accepted Standard Model result. In the NuTeV analysis a non-trivial correction must be made for the small neutron excess in the steel target. We found that these additional neutrons have another, hitherto neglected effect, namely they generate an isovector-vector field which modifies the structure of all nucleons in the target. This represents a new correction for the NuTeV experiment, that explains roughly half of the disagreement with the Standard Model. We will discuss the impact of this result on our understanding of the structure of bound nucleons and also highlight some further ramifications, for example, in parity violating deep inelastic scattering on nuclear targets.

Hosted by Tatsu Takeuchi

We study the classical motion of some string configurations in asymptotically AdS_5 backgrounds. We argue that for some configurations the motion is chaotic. Using the AdS/CFT correspondence we comment on the implications of this classical chaotic motion on the dual field theory and its possible implications for black hole physics.

Gauged extension of the Standard Model is one possible scenario with new physics below the electroweak scale. In the minimal extension of the Standard Model it is possible to gauge any one of the following global symmetries in an anomaly free way: (i) L_e-L_μ, (ii) L_e-L_τ or (iii) L_μ-L_τ. If the gauge boson corresponding to (i) or (ii) is (nearly) massless then it will show up as a long-range flavor-dependent fifth force between macroscopic objects. Such a force can significantly influence the neutrino oscillations due to its flavor dependence and long-range nature in spite of very strong constraints on the relevant gauge couplings from the fifth force experiments. We study the impact of the L_e-L_{{μ, τ}} potential of the electrons in the Sun and Earth on the long baseline neutrino oscillation experiments. It is observed that the new forces change the standard picture in a qualitatively different way which ultimately results in a strong bound on the couplings of these forces.

We utilize the tools of the gauge/gravity correspondence in order to investigate electroweak symmetry breaking (EWSB). For quite some time now, a walking technicolor sector has been viewed by phenomenologists as a very promising alternative to the Higgs boson. Unfortunately however, no precise computations have been possible since in the technicolor gauge theory EWSB is due to strong-coupling dynamics. Using recent developments in the gauge/gravity duality, we construct a gravity dual of a walking technicolor model and aim to compute the Peskin-Takeuchi S-parameter, which is an observable that can distinguish between a Higgs and a technicolor sector.

We propose a string theory of turbulence that explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions. This string theory of turbulence should be understood in light of the AdS/CFT dictionary. Our argument is crucially based on the use of Migdal's loop variables and the self-consistent solutions of Migdal's loop equations for turbulence. In particular, there is an area law for turbulence in 2+1 dimensions related to the Kraichnan scaling.

I will discuss important sub-structure that arises in the supersymmetric moduli space of heterotic theories. Smooth heterotic theories typically only admit supersymmetric gauge configurations in a part their Kahler cone and the presence of boundary walls between supersymmetric and non-supersymmetric regions can have significant phenomenological effects. Specifically, I will discuss heterotic supersymmetry and vector bundle slope stability from an effective field theory point of view and discuss physical applications of this description including branch structure which allows for transitions between effective theories, constraints on yukawa couplings and moduli stabilization.

Even if new physics beyond the Standard Model indeed exists, the energy scale of new physics might be beyond the LHC search reach and the LHC experiment could find only the Higgs boson but nothing else. This is the so-called particle physicists' Nightmare Scenario. On the other hand, the existence of the dark matter has been established from various observations and one of promising candidates for thermal relic dark matter is a stable and charge-neutral Weakly Interacting Massive Particle (WIMP) with mass in the range of GeV to TeV, below the energy of LHC experiment. In the nightmare scenario, we introduce such a dark matter particle singlet under the Standard Model gauge group, which only couples to the Higgs doublet at the lowest order, and investigate a possibility that the dark matter particle can overcome the nightmare via various phenomenologies such as the dark matter relic abundance, the direct detection experiments for the dark matter particle, and the LHC physics.

Hosted by Tatsu Takeuchi

Quasars are among the most luminous and the most distant objects in the Universe. Consequently they are particularly interesting to probe its origin and to understand its evolution. However, the huge distances at which these objects are generally found prevent us from resolving their central regions so that we cannot directly check the validity of the geometrical as well as the dynamical models accounting for their observational properties (spectral energy distribution, line profiles, presence or absence of radio jets etc). In our thesis, we use two indirect observational techniques in order to constrain the existing models. These techniques which are particularly sensitive to the geometricalstructure of the quasar emission regions are polarimetry and gravitationalmicrolensing.In the first part of our thesis we study the correlation between the direction of the linear polarization and the orientation of the hostgalaxy/ extended emission that we determined on the basis of high resolution HST images. We show how this study enables us to bring new clues favoring the existence of a unification model for the Type 1 and Type 2 quasars. In the second part, we show how gravitational microlensing allows to constrain the geometry and size of the regions at the origin of the broad absorption lines observed in the spectrum of 10 to 20 % of quasars. For this purpose we build a radiative transfer code allowing to simulate the line profiles produced in a variety of realistic wind models. These models are then used to study the variations of line profiles induced by the transit of a gravitational microlens. This technique is finally applied to the case of the quasar H1413+117 in order to determine the geometry of the regions which produce the broad absorption lines.