AEI-Kolloquium

Datum	Vortrag	Redner/in	Institut
10. 9. 09	Cosmology with 300,000 Standard Sirens	Dr. Curt Cutler	Jet Propulsion Laboratory, Pasadena
17. 9. 09	Gravitational wave detection using pulsars: a Bayesian analysis	Rutger van Haasteren	Universiteit Leiden/Netherlands
24. 9. 09	Acceleration noise sources in drag-free spacecraft: Gravitational disturbances	Dr. Antonio Pulido Patón	Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, P.R. China
22. 10. 09	Gamma-Ray Bursts and Gravitational Waves: a tool for multi-messenger astrophysics	Dr. Alessandra Corsi	University of Rome "Sapienza"
29. 10. 09	Overview of the current research in the IGR	Prof. Sheila Rowan	Univ. of Glasgow
5. 11. 09	Gravitational waves from cosmological sources.	Dr. Xavier Siemens	University of Wisconsin
12. 11. 09	Gravity, quantum physics, and the universe	Dr. Martin Bojowald	PENNSTATE University, USA
26. 11. 09	The Massive Black Hole and Nuclear Star Cluster of the Milky Way.	Prof. Reinhard Genzel	MPI for Extraterrestrial Physics Garching, Germany & Department of Physics, University of California, Berkeley
3. 12. 09	The Evaporating ACO Cosmic String Loop	Dr.Malcolm Anderson	Mathematics, Faculty of Science, Universiti Brunei Darussalam
17. 12. 09	LSC-Virgo Meeting Boston 14 - 17 Dec.
24. 12. 09	Christmas
31. 12. 09	New Year's Eve
28. 1. 10	Beyond the B12. Quantum experiments with membranes	Dr. Stefan Danilishin	Moscow State University
18. 2. 10	What's new in EAGLE 5? / Neuerungen in EAGLE 5;	Andreas Weidner	AEI Hannover
11. 3. 10	8. - 12. 3. DPG-Frühjahrstagung Hannover
18. 3. 10	Quantum gates for linear optics quantum information processing	Dr. Jaromir Fiurasek	Palacky University, Olomouc, Czech Republic
8. 4. 10	Identifying and subtracting noise transients in gravitational-wave detectors	Dr. Ajith Parameswaran	California Institute of Technology
15. 4. 10	Cosmology as Science: From Inflation to Eternity	Prof. Lawrence Krauss	School of Earth and Space Exploration and Physics Dept. Arizona State University
22. 4. 10	Dynamical mini-collapses in rotating neutron stars and instabilities induced by phase transitions	Dr. Michal Bejger	Nicolaus Copernicus Astronomical Center, Warsaw / Poland
3. 5. 10	A Pulsar Timing Array for Gravitational Wave Detection	Dr. Maura McLaughlin	West Virginia University USA
13. 5. 10	Ascension Day
3. 6. 10	The polynomial search: an all-sky search for gravitational waves from neutron stars in binary systems	Sipho van der Putten	Nikhef, Amsterdam
10. 6. 10	LSC-Virgo Meeting Novotel Hannover 7 - 10 June
17. 6. 10	RF-Driven Electric Micropropulsion Systems for Precise Attitude Control and Formation Flying Applications	Dr. Davar Feili	I. Physik. Inst. Justus-Liebig-Univ. Gießen
24. 6. 10	Precision Pulsar Timing for GW Detection: Interstellar Matters	Prof. James Cordes	Cornell Univ., Ithaca / USA
22. 7. 10	Quantifying the Impact of Data Quality on Searches for Gravitational Waves from Binary Coalescing Systems with LIGO	Jacob Slutsky	Louisiana State University, Baton Rouge / USA
29. 7. 10	Magnetars, Supernovae, and GEO	Dr. Peter Kalmus	California Institute of Technology - LIGO Laboratory, Pasadena
16. 9. 10	Quantum Hindsight: Quantum Parameter Estimation Using Smoothing	Assoc. Prof. Elanor Huntington	Univ. of New South Wales at the Australian Defence Force Academy, Canberra
23. 9. 10	LSC-Virgo Meeting Cracow 20 - 24 Sept.
28. 10. 10	Bursters, Burpers, and Repeaters: Charting the Transient Radio Sky on Sub-Second Time-Scales with LOFAR	Dr. Jason W.T. Hessels	Netherlands Institute for Radio Astronomy (ASTRON) and University of Amsterdam
2. 12. 10	Gravitational Waves detection: when no plan is the best plan	Dr. Gian Mario Manca	AEI Golm
16. 12. 10	LISA and GW Bursts from Cosmic (super-)Strings	Dr. Curt Cutler	Jet Propulsion Laboratory, USA
20. 1. 11	Gravitational waves from first order phase transitions	Dr. Chiara Caprini	Institute de Phys. Theoretique, Gif-sur-Yvette, France
3. 3. 11	X-ray Pulsars and the Road to Discovery	Dr. Eric Gotthelf	Columbia Astrophysics Laboratory, Columbia University, New York/USA
10. 3. 11	High-precision space inertial sensor and its application	Dr. Bai Yan-Zheng	Huazhong University of Science and Technology (HUST) - China
17. 3. 11	LSC-Virgo Meeting Arcadia 12 - 17 March
24. 3. 11	Starting business	Dr. Maximilian C. Rogge	Leibniz Universität Hannover
11. 4. 11	Many Core Accelerated (GPU) Supercomputing in China and elsewhere - black holes and gravitational waves from galactic nuclei	Prof. Dr. Rainer Spurzem	National Astronomical Observatories, Chinese Academy of Sciences, Beijing and Astronomisches Rechen-Inst., Zentrum fuer Astronomie, Univ. Heidelberg
15. 4. 11 11:00 Uhr	Development of Laser Interferometer in SLI Group	Yu-rong Liang	Huazhong University of Science and Technology, Wuhan, P.R. of China
21. 4. 11	Broadband Searches for Continuous-Wave Gravitation Radiation with LIGO	Dr. Vladimir Dergachev	Caltech, Pasadena
26. 5. 11 10:30 Uhr	The Status of Pulsar Timing Efforts in Gravitational Wave Detection	Dr. Joris Verbiest	Max-Planck-Institut für Radioastronomie, Bonn
9. 6. 11	LSC-Virgo Meeting LAL Orsay 6 - 9 June
14. 6. 11 Tuesday 11:00 h	Low Frequency Vibration Isolation and Alignment System for Advanced Ligo	Dr. Wensheng Hua	Freelancer, Fremont / USA
16. 6. 11	Recent results from Neutrino Telescopes	Dr. Antoine Kouchner	AstroParticule et Cosmologie, Université Paris 7
17. 6.  11 Friday 10:00 h	Advanced Execution Models for Extreme Scale Computing	Prof. Thomas Sterling	Edwards and Arnaud Professor of Computer Science, Department of Computer Science and Center for Computation and Technology, Louisiana State University, Baton Rouge/USA
29. 6. 11 Wednesday 13:15 h	Using numerical relativity to explore fundamental physics and astrophysics	Dr. Luciano Rezzolla	Albert Einstein Institute, Max-Planck Institute for Gravitational Physics, Potsdam, Germany
7. 7. 11	Fermi LAT observations of gamma-ray pulsars	Dr. Lucas Guillemot	MPI for Radio Astronomy, bonn
11. 8. 11	GW Astrophysics with compact binaries	Dr. Ilya Mandel	MIT Kavli Institute, Cambridge, USA
18. 8. 11	BOINC Workshop, AEI Hannover 17 - 18 August
1. 9. 11	When one black hole is not like the other	Dr. Steve Drasco	California Polytechnic State University, Physics Dept., San Luis Obispo / USA
15. 9. 11	Digitally Enhanced Interferometry	Andrew Sutton	The Australian National University, Dept. of Quantum Science, Canberra / Australia
22. 9. 11	LSC-Virgo Meeting Gainesville 24 - 29 September
10. 11. 11	Neutron Star Radii and Masses	Prof. Feryal Özel	University of Arizona, Tucson, USA
8. 12. 11	Stars, elements, and our cosmic inheritance	Dr. Marialuisa Aliotta	School of Physics and Astronomy, University of Edinburgh
19. 1. 12	Gamma ray pulsars: towards a high energy census of the Milky Way	Dr. David Smith	C.E.N. de Bordeaux-Gradignan
9. 2. 12	Coherent Network Analysis	Dr. Sergey Klimenko	University of Florida, Gainesville
22. 3. 12	LSC-Virgo Meeting MIT Cambridge/Boston 19 - 23 March
29. 3. 12	Energy and the Environment Block Lecture 29-30 March both days 9:00-17:00 Prof. K. Danzmann, LUH Hannover and Dr. S. Hild, University of Glasgow
12. 4. 12	Probing Dark Energy and fundamental physics with galaxy cluster surveys	Dr. Shantanu Desai	Universitätssternwarte der LMU München
19. 4. 12	t.b.a.	Dr. Robert Caldwell	Dartmouth College, Hanover, USA.
26. 4. 12	Discovery of gamma-ray pulsars in blind searches of Fermi-LAT data using new methods inspired from gravitational-wave astronomy	Dr. Holger Pletsch	AEI Hannover
3. 5. 12	3rd ASPERA Computing and Astroparticle Physics Workshop 3-4 May, AEI Hannover
10. 5. 12	t.b.a.	Dr. René Breton	University of Southampton, U.K.
7. 6. 12	GWPAW Meeting Hannover 4 - 7 June

Abstracts

2008

13. 11. 2008: "A Synaptic Numerical Relativity", L. Rezzolla
I will review the work done in numerical relativity at the AEI/Potsdam and highlight how numerical relativity is becoming more and more the bridge between different aspects of relativity, as well as the bridge between relativity and other branches of physics. I will do this by illustrating specific examples on how numerical calculations have an impact on the physics of black holes, on the physics of neutron stars and on gravitational-wave data analysis.

20. 11. 2008: "Indeterminacy of Holographic Quantum Geometry", Craig J. Hogan
Theoretical results suggest that quantum spacetime displays a remarkable holographic property: the world we describe as a classical spacetime emerges out of a quantum theory on two dimensional sheets that appear in our world to move at the speed of light; in addition all dimensions display a minimum length or time, and a maximum frequency at the Planck scale. The talk will review these ideas and show how such theories lead to a surprisingly large indeterminacy of position, transverse to light sheets, at macroscopic separation. The effect appear in interferometers as a new kind of "holographic noise" whose properties can be predicted from gravitational thermodynamics with no parameters. This noise is a candidate for the "mystery noise" currently appearing at GEO600.

2009

5. 2. 2009: "Experimental investigation of a control scheme for a zero-detuning resonant sideband extraction interferometer for next-generation gravitational-wave detectors", Fumiko Kawazoe
Some next-generation gravitational-wave detectors, such as the American Advanced LIGO project and the Japanese LCGT project, plan to use power recycled resonant sideband extraction (RSE) interferometers for their interferometer's optical configuration. A power recycled zero-detuning (PRZD) RSE interferometer, which is the default design for LCGT, has five main length degrees of freedom that need to be controlled in order to operate a gravitational-wave detector. This task is expected to be very challenging because of the complexity of optical configuration. A new control scheme for a PRZD RSE interferometer has been developed and tested with a prototype interferometer. The PRZD RSE interferometer was successfully locked with the control scheme. It is the first experimental demonstration of a PRZD RSE interferometer with suspended test masses. The result serves as an important step for the operation of LCGT.

19. 2. 2009: "Gravitational Wave Burst Detection Using Pulsars", Andrea Lommen
At the time of this talk, pulsar timing for gravitational wave detection will be in the midst of becoming an internationally coordinated effort. I will review the idea of using pulsars to detect a very low-frequency stochastic background of gravitational waves, and discuss current limits that pulsar timing places on the energy density of gravitational waves and what those limits correspond to in terms of cosmological models, most notably the merger rate of super-massive black holes in the early universe. I have become interested in the possibility of taking these ideas farther and using pulsar timing to detect bursts of gravitational radiation from a number of different possible sources, which I will describe.

26. 2. 2009: "Aspects of Multimessenger Astrophysics", Szabolcs Márka
Gamma-ray, X-ray, optical, radio and neutrino observations of cataclysmic cosmic events with plausible gravitational wave emission are being used in combination with searches for gravitational waves. Beyond the benefit of a potential discovery, multimessenger approaches might allow us to answer important scientific questions, which would be out of reach for a single messenger detector. Information on the progenitor, such as trigger time, direction and expected frequency range, shall enhance our ability to identify gravitational wave signatures with amplitude close to the noise floor of the detector. Even in the absence of detection, the association of the astrophysical trigger with a known source distance can allow to set upper limits on the energy emitted in gravitational waves. Results from past multimessenger based gravitational wave searches will be summarized. A personal view on the future of multimessenger searches, a survey of cosmic source candidates, and a peek at possible science reach of future searches will also be mentioned.

12. 3. 2009: "A model for Alfvén QPOs in magnetars", Nikolaos Stergioulas
We discuss simulations of Alfven oscillations in magnetars, modeled as relativistic stars with a dipolar magnetic field. We use the anelastic approximation to general relativistic magnetohydrodynamics, which allows for an effective suppression of fluid modes and an accurate description of Alfven waves. In addition, we compute Alfven oscillation frequencies along individual magnetic field lines with a semi-analytic approach. The continuum obtained with our semi-analytic approach agrees remarkably well with QPOs obtained via the numerical simulations, allowing for a clear interpretation of the QPOs as corresponding to turning points of the continuum. We construct empirical relations for the QPO frequencies and compare them to observations of known Soft Gamma Repeaters. We find that, if QPOs are produced by Alfven oscillations near the magnetic pole, then one can place an upper limit to the mean surface strength of the magnetic field of 8 times 10 G.Finally, we discuss the implications of our model for the detection of gravitational waves from compact stars.

19. 3. 2009: "LISA technology developments and their applications to lidar missions", Kenji Numata
In this seminar, I will talk about my researches at NASA Goddard Space Flight Center. They include interferometric testbed and fiber lasers for LISA, optical parametric devices for trace gas detection on mars and earth, and laser systems for earth’s carbon dioxide monitoring.

26. 3.2009: "Radio Pulsars: The Gifts that Keep on Giving", Scott Ransom
There are about 2000 pulsars known, and while all of them as neutron stars are fascinating objects, the best and most exciting science comes from a very small percentage (~1%) of exotic objects. Within the past 5–6 years, many such systems have been uncovered, and they are providing a wealth of science. In this talk I'll briefly cover 3 new results from exotic pulsars that have recently been (or will hopefully soon be) published in Science. The first is the detection of relativistic precession from the double pulsar (as measured through changes in eclipse shape!). The second is the discovery of a true millisecond pulsar (MSP) in an eccentric orbit around a likely main sequence star in the Galactic disk (systems like that "shouldn't" exist, and in this case the pulsar is also quite massive at ~1.7 M_sun). And finally, the third is the discovery of a very bright radio MSP which appears to have just been created and is still in transition from its low-mass x-ray binary stage – a missing-link in the MSP creation process.

9. 4. 2009: "Spaceborne Gravimetry as a Geodetic Remote Sensing Tool for Earth Sciences", Nico Sneeuw
The GRACE satellite mission has established spaceborne gravimetry as a remote sensing tool serving several earth science disciplines. Global mass transports in and between the atmosphere, hydrosphere, and cryosphere can be monitored at long wavelengths. The GRACE success and the expected success of GOCE have raised an appetite in the community for more. And better. After a brief historical introduction into geodesy this presentation will discuss techniques and tools for gravity field mapping. In particular the principles will be examined how gravity is determined from free fall in space. A number of recent GRACE results are shown to exemplify the success of the mission. Eventually the requirements and design options for a future gravity field mission will be discussed, e.g. formation flying, multi-satellite configurations, laser SST vs. gradiometry.

16. 4. 2009: "Die Nanokraftmesseinrichtung der PTB – Die wichtigsten Anwendungen", Dr. Vladimir Nesterov
Das Arbeitsprinzip und die Kalibriermethode der Nanokraftmesseinrichtung werden vorgestellt. Als erste Nanokraftmessung an der Grenze der Empfindlichkeit des Messsystems wurde an Luft die Kraft aufgrund des Lichtdruckes eines 7 mW He-Ne Lasers bestimmt. Wichtigste Anwendungen der Nanokraftmesseinrichtung sind die Kalibrierung von Transfernormalen und Nanokraftaktoren. Abschließend wird eine neue Methode zur Präzisionsmessung der Permittivität des Vakuums bei Frequenzen < 1 Hz vorgestellt. (Gibt es eine "Dispersion des Vakuums"?).

23. 4. 2009: "Efficient generation of EMRI gravitational waveforms", Dr. Gaurav Khanna
In this talk I will present an efficient technique for generating gravitational waveform template data as needed by various gravitational wave observatories (LIGO, GEO, LISA etc) for matched-filtering. The technique involves making use of approximations to the source modeling and hardware accelerators for the numerical computation. In particular, I will present use of Kerr black hole perturbation theory applied to the case of extreme-mass-ratio binary black hole inspiral (EMRI). EMRIs are common occurrences in galactic nuclei and produce gravitational radiation that is likely to be detected by the ESA/NASA LISA mission.

30. 4. 2009: "Earth Gravity Field Satellite Missions as Precision Measurement Laboratories", Jakob Flury
The GRACE satellite missions has proven the potential of satellite techniques to recover the global gravity field and to detect and quantify mass changes in the Earth system. With GRACE, mass change in the polar ice sheets, oceans, in hydrology, and within the solid Earth has been observed, opening new horizons for geodesy and Earth sciences. The twin GRACE satellites are flying measurement laboratories combining very precise inter-satellite ranging, accelerometry and attitude sensors. For a full exploitation of the sensor potential, a precise understanding of satellite platform laboratory conditions is needed. Analysis of GRACE observation time series has revealed a number of disturbances, e.g., due to thermal control and attitude control systems. At the same time, the high-resolution observation time series allow new, very detailed insight into the dynamics of drag and radiation acting on the satellites. The presentation will show examples for such effects and discuss improvements needed for an exploitation of next generation sensor technology such as inter-satellite laser ranging for geodetic missions.

7. 5. 2009: "Pulsars as probes for gravitational physics", Michael Kramer
Pulsars are incredibly useful tools to study a wide variety of fundamental physics, in particular gravitational physics. This is possible due to their simultaneous nature as accurate cosmic clocks and massive test particles. In this talk I present some of the best experiments made to date, providing stringent tests on the validity of general relativity and other theories of gravity. I will also discuss how we find such sources and how we will continue to do so in the future.

28. 5. 2009: " Searching for periodic gravitational wave signals", Andrzej Krolak
I shall review data analysis tools required in order to search for periodic gravitational wave signals. The tools are: an appropriate statistic, an equation for false alarm probability, a grid in the parameter space, numerical algorithms, an upper limit estimation. The methods presented apply to search for gravitational waves from rotating neutron stars in ground base detector data and to search for gravitational waves from compact binary systems in space borne LISA detector data.

20. 8. 2009: "Effective action and quantum gravity", Yuri Gussev
Quantum field theory, originally developed in the elementary particle physics, turned out to be powerful methods that found applications in many other areas. The low energy approximation of a field theory can be derived by techniques known as the effective field theory. These techniques are at the center of renewed interest in QFT in curved spacetime, often called quantum gravity. In this talk we will overview methods and applications of its central object, the effective action. The focus is on explicitly covariant methods such as the covariant perturbation theory. The effective action approach is especially suited for solving the quantum black hole evolution. However, the effective action may also be relevant to the gravitational wave physics, albeit in indirect ways.

17. 9. 2009: "Gravitational wave detection using pulsars: a Bayesian analysis", Rutger van Haasteren
Several pulsar timing projects (PTAs) have been initiated around the globe to detect astrophysical gravitational-waves like the stochastic background. We are now entering the era where such a detection can become reality, and a careful analysis of these projects and the data is needed. Along with some basic PTA theory, I will present our Bayesian data analysis algorithm for these PTAs, and I will discuss the prospects for gravitational-wave detection; some single-sources and the stochastic background. As part of the European PTA (EPTA) project, I will also show the results of the recent unpublished EPTA data analysis. This has resulted in the first EPTA-only upper limits on the stochastic gravitational-wave background.

2012

09. 02. 2012: "Coherent Network Analysis", Dr. Sergey Klimenko
The inverse problem - reconstruction of gravitational wave (GW) events and their parameters from signals recorded by detectors - is central in the GW data analysis. Usually it is divided in two parts: separation of GW signals from the detector noise and estimation of the signal parameters, resulting in various detection statistics and methods for the source reconstruction. However, in general, these two parts should be considered together within the same analysis framework, called coherent network analysis, which coherently combines data from all detectors. In my talk I will describe coherent network analysis in application to detection of poorly modeled transient GW sources, and discuss the existing/future GW detector networks and their capabilities for detection, sky localization and reconstruction of source parameters.