IRTG PhD days 2011

4 Oct 2011, 09:00 → 5 Oct 2011, 23:00 Europe/Berlin

Seminar room 052, building 69, ground floor (Desy)

Benedikt Vormwald (DESY Hamburg), Falk Lindner, Hannes-Sebastian Zechlin (Department Physik, Universitaet Hamburg), Julia Harz (DESY Hamburg), Martin Schasny, Sergei Bobrovskyi (University of Hamburg)

The Collaborative Research Center 676 (SFB 676) at Hamburg University and the cluster of excellence LEXI at Hamburg University and DESY are research programs at the interface of particle physics, string theory and cosmology. Significant developments are taking place in each of these fields, and far-reaching scientific results are expected in the course of the next 20 years.

Many PhD students are involved in the different SFB and LEXI research fields and organized in a structured graduate program, the “Integrated Research Training Group” (IRTG). In order to benefit from the given experience in different fields, this two-days workshop is meant to bring PhD students and experienced international researchers together and create a platform for discussions, exchange and new ideas.

Besides two main lecture courses given by highly experienced speakers, PhD students will get the opportunity to present and discuss their own work related to the SFB and LEXI research topics.

Tuesday 4 October

09:00 → 09:10 Welcome

09:10 → 10:30 Mysteries of modern physics - Part 1

Lecture part 1

Speaker: Dr John Ellis

10:30 → 11:00 Coffee break

11:00 → 12:30 Mysteries of modern physics - Part 2

Lecture part 2

Speaker: Dr John Ellis

12:30 → 14:00 Lunch break

14:00 → 15:40 Student session

Convener: Sergei Bobrovskyi (University of Hamburg)

14:00 Registration

14:10 IRTG student council

Slides vortrag-phddays.pdf

14:20 Three Open Questions of Early Universe Cosmology -- One Common Answer

Speaker: Mr Kai Schmitz (DESY Hamburg)

Slides schmitz_kai_phddays.pdf

15:30 DoIT - The PhD Initiative at DESY

DoIT is a representation run by PhD students. We are in close contact with the DESY Directorate and other (administrative) bodies at DESY. We can give advice on all things concerning PhD students.

Speaker: Mr Marc Wenskat (DESY)

Slides DoIt-PhDDays.pdf

15:40 → 16:00 Coffee break

16:00 → 17:40 Student session

Convener: Mr Hannes-Sebastian Zechlin (Department Physik, Universitaet Hamburg)

16:00 Long-Lived staus - a promising signature at colliders

Abstract will be given later.

Speaker: Mr Jan Heisig (University of Hamburg)

Slides 0_Heisig_PhD_days.pdf

16:20 Cosmology meets neutrino physics

Speaker: Ms Valerie Domcke (DESY)

Slides PhDdays_Valerie_Domcke.pdf

16:40 Transition-Edge Sensor: A new detector for the ALPS experiment

The ALPS (Any Light Particle Search) experiment, located at DESY, goes in its second phase. To increase the sensitivity the experiment will be bigger and fancier: more laser power, a regeneration cavity and longer cavities. Besides of that improvements the collaboration is also looking for a new, more sensitive detector. Because of the intrinsic noise of the CCD -- the present detector of ALPS -- now studies have started to build up an cryogenic single infrared photon detector. For that we use a Transition-Edge Sensor (TES), which is working at a superconducting transition in a Milli Kelvin range. In this talk the principle of such a detector is explained and the application to ALPS and an overview of the recent work is given.

Speaker: Mr Jan Dreyling-Eschweiler (DESY)

Slides phd-days_dreyling-eschweiler.pdf

17:00 Cosmic Rays in the Galactic Magnetic Field

Cosmic rays with energies up to 10^20 eV have been seen by the Pierre Auger Collaboration and other experiments. There are still many unanswered question concerning cosmic rays in this ultra-high-energy regime. For instance the measured structure of the flux, the incoming direction and the composition of the cosmic rays still bare question-marks. A possible explanation for these three problems, involving the interaction of these cosmic rays with the galactic magnetic field, will be presented in this talk.

Speaker: Mr Arjen van Vliet (DESY)

Slides

• 9-0-ARvanVliet.pptx
• ARvanVliet.pptx
• Backup_Slides.pptx

18:00 → 19:00 arxiv vs. snarxiv

Slides gaming.pdf

19:00 → 23:30 Barbecue

Get-together of all IRTG students

Wednesday 5 October

09:00 → 10:30 Physics at the smallest scales - Part 1

Lecture part 1

Speaker: Dr Carlo Rovelli

10:30 → 11:00 Coffee break

11:00 → 12:30 Physics at the smallest scales - Part 2

Lecture part 2

Speaker: Dr Carlo Rovelli

12:30 → 14:00 Lunch break

14:00 → 16:00 Student session

Convener: Mr Benedikt Vormwald (DESY Hamburg)

14:00 Quasi-stable neutralinos @ LHC

Speaker: Mr Jan Hajer (DESY)

Slides Hajer.pdf

14:20 Beyond the speed of light - Propagation of of the scalar field on Finsler spacetime

Finsler spacetime manifolds are generalizations of Lorentz spacetime manifolds due to the use of Finsler geometry instead of Lorentz geometry. In this talk I present results on the propagation of the free scalar field on Finsler spacetimes. On a specific Finsler spacetime that is a small departure from Minkowski spacetime I present the dispersion relation of the particle modes of the free scalar field and study the resulting particle velocity.

Speaker: Mr Christian Pfeifer (II Institute for Theoretical Physics, Uni Hamburg)

Slides ScalarFieldFinslerSpacetimeFinal2.pdf

14:40 Tunneling Solutions in Scalar Field Theory

In this talk I will present new, exact tunneling solutions for different potentials. I will also comment on applications in cosmology.

Speaker: Ms Cecelie Hector (DESY Theory)

Slides hector_phddays2011talk.pdf

15:00 A sufficient condition for de Sitter vacua in type IIB string theory

We derive a sufficient condition for realizing meta-stable de Sitter vacua with small positive cosmological constant within type IIB string theory flux compactifications with spontaneously broken supersymmetry. There are a number of `lamp post' constructions of de Sitter vacua in type IIB string theory and supergravity. We show that one of them -- the method of `K\"ahler uplifting' by F-terms from an interplay between non-perturbative effects and the leading $\alpha'$-correction -- allows for a more general parametric understanding of the existence of de Sitter vacua. The result is a condition on the values of the flux induced superpotential and the topological data of the Calabi-Yau compactification, which guarantees the existence of a meta-stable de Sitter vacuum if met. Our analysis explicitly includes the stabilization of all moduli, i.e. the K\"ahler, dilaton and complex structure moduli, by the interplay of the leading perturbative and non-perturbative effects at parametrically large volume.

Speaker: Mr Markus Rummel (University of Hamburg)

Slides deSitterIIB_MarkusRummel_FINAL2.pdf