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Talks/Seminars



Here you find the upcoming and past talks and colloquia. The colour code and abbreviations:
Seminar of the Institute Quantum Theory Seminar General Relativity Seminar
Video seminar of the SFB Colloquium of the Faculty Other Talks
Seminar of Research Training Group

HS: Hörsaal (Lecture Hall), SR: Seminarraum (Seminar room), URZ Universitätsrechenzentrum (Computer Center)




Upcoming Talks

Wed, 2015-02-11 16:15
tba
from Oliver Rinne



Calendar

January 2015
Su Mo Tu We Th Fr Sa
28 29 30 31 01 02 03
04 05 06 07 08 09 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
01 02 03 04 05 06 07

February 2015
Su Mo Tu We Th Fr Sa
01 02 03 04 05 06 07
08 09 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
01 02 03 04 05 06 07

You can also access a full calendar with extended functionality.



Past Talks




Talks from 2014-10-01 up to Today
Fri, 2015-01-30 16:15(HS 2, Abbeanum)
Orthodox heresies on gravitational waves
Patrick Dürr, Universität Tübingen

Abstract:
We shall argue that the orthodox claim that gravitational waves (GWs) possess energy momentum is inconsistent with General Relativity (GR): It is an artifact of forcing GR into a linear Newtonian/Minkowskian field theoretical framework, a framework ultimately alien to and incompatible with Einstein's geometrodynamical GR, both mathematico-physically and conceptually. Only within such a Newtonian/Minkowskian framework does a global energy conservation law hold, as expressed in the local form of a continuity equation. GR as the more fundamental theory forces us to revise this framework and adopt a modified conservation law in its right. Taking GR at face value, a consistently general-relativistic explanation is offered for the two main arguments usually adduced to justify the assignment of energy to GWs, the effects on test masses and Feynman's Sticky Bead Argument. Potential consequences and open questions in line with the preceding considerations will be sketched, touching on the standard interpretation of Hulse Taylor-like double pulsars, quantum gravity, GW-induced instabilities in neutron stars, cosmology and the ontological status of GWs.
Wed, 2015-01-28 17:15(Seminarraum HI Jena, Fröbelstieg 3)
Lightlike inhomogenities in worldline pair creation
Dr. Anton Ilderton, Chalmers University Göteborg

The locally constant field approximation (LFCA) is commonly used to calculate the nonperturbative pair production probability in electromagnetic fields.
In certain classes of fields, for example longitudinal electric fields depending on lightfront time, the LCFA is known to be exact. Using the worldline description of the effective action, we show that the reason for this is closely tied to the zero-mode problem of lightfront quantisation, and the so-called “triviality” of the lightfront vacuum.
Tue, 2015-01-27 16:15(SR 5, Helmholtzweg 4)
The Callias Index Theorem Revisited
Dr. Marcus Waurick, Technische Universität Dresden
Wed, 2015-01-21 16:15(HS 2, Abbeanum)
New Frontiers in integrated photonics: supersymmetry and unphysical phenomena
Prof. Dr. Alexander Szameit, IAP Universität Jena
Tue, 2015-01-20 16:15(SR 5, Helmholtzweg 4)
Asymptotic Safety in Gravity
Dr. Astrid Eichhorn, Imperial College London
Wed, 2015-01-14 16:00(SR 309, Carl-Zeiß-Str. 3)
From Schwarzschild to General Relativity: modeling physical phenomena with the help of geometry
Dr. Carla Cederbaum, Universität Tübingen
Tue, 2015-01-13 16:15
Spectral theory for continuum one-dimensional quasicrystal models
Dr. Christian Seifert, Technische Universität Hamburg-Harburg

We consider an ergodic family $(H_\omega)_{\omega\in\Omega}$ of continuum one-dimensional Schr\"odinger operators, where we allow for measures as potentials. We show that the random operator $H$ has Cantor type spectra of Lebesuge measure zero under suitable finite local complexity conditions on the potentials. Such operator families appear in the study of quasicrystalline models.
Thu, 2015-01-08 14:15(SR 5, HH 4, instead of the quantum theory seminar)
Perturbative Quantum Gravity III
Prof. Ilya Shapiro
Universidade Federal de Juiz de Fora
Wed, 2015-01-07 16:15(HS 2, Abbe., instead of the seminar of the institute)
Perturbative Quantum Gravity II
Prof. Ilya Shapiro
Universidade Federal de Juiz de Fora
Tue, 2015-01-06 16:15(SR 5, Helmholtzweg 4)
Perturbative Quantum Gravity I
Prof. Ilya Shapiro
Universidade Federal de Juiz de Fora
Thu, 2014-12-18 14:15
Critical behavior in spherical and hyperbolic space
Dr. Dario Benedetti (AEI Potsdam)
Wed, 2014-12-17 16:15
A Simple Proof of the Kochen-Specker Theorem on the Problem of Hidden Variables
Prof. Norbert Straumann, Universität Zürich
Tue, 2014-12-16 16:15(SR 5, Helmholtzweg 4)
Rendering integrands positive - subset method for lattice QCD at high density
Dr. Falk Bruckmann
Universität Regensburg
Wed, 2014-12-10 16:00(HS 2, Abbeanum)
apl.: AG Fachdidaktik der Physik und Astronomie
Prof. Lotze
Tue, 2014-12-09 16:15(SR 5, Helmholtzweg 4)
(Non)-Fermi Liquids
Dr. Tilman Enss
Ruprecht-Karls-Universität Heidelberg
Fri, 2014-12-05 11:30(Rosensäle)
Binary neutron stars: what we understand and what we don't
From Luciano Rezzolla for the GWA14 conference

I will review the recent progress made in modelling binaries of compact stars and the role played by magnetic fields and the equation of state in their evolution. Special attention will be paid to highlighting how the progress of ab-initio fully relativitistic calculations can be used to explain several aspects of the phenomenology of short gamma-ray burst, but also how new observations on the X-ray afterglows represent new riddles for the theoretical modeling.
Fri, 2014-12-05 10:00(Rosensäle)
Constraining the nature of gravitational waves with binary pulsar experiments
From Paulo Freire for the GWA14 conference

In this talk I present some recent pulsar timing experiments for double neutron stars that test general relativity's quadrupolar gravitational wave emission formula with unprecedented precision. I then present the results of timing of millisecond pulsar - white dwarf systems that severely constrain the emission of dipolar gravitational waves (DGW) for a wide range of neutron star masses. Apart from constraining (and in some cases excluding) alternative theories of gravity that predict DGW emission, these results reinforce our confidence in the templates being used to search for the GW signal of NS-NS and NS-BH inspiral events in the advanced LIGO and Virgo detectors.
Fri, 2014-12-05 09:00(Rosensäle)
Highest order post-Newtonian dynamics of non-spinning and spinning compact binaries in general relativity
From Gerhard Schäfer for the GWA14 conference

The talk delivers insight into the calculations of highest order post-Newtonian (PN) Hamiltonians for binary black holes. The conservative dynamics is presented up to 4 PN order for binaries with both non-spinning and spinning components, where the spins are counted of 0.5 PN order. The related dissipative radiation reaction dynamics is known up to 4.5 PN order. As application, the Innermost Stable Circular Orbit for spinless binaries is given through 4 PN order and the test-body limit is compared with the exactly known ISCO of a test-body orbiting a Schwarzschild black hole.
Thu, 2014-12-04 10:00(Rosensäle)
Binary black holes: Waveform modeling and two-body dynamics
From Harald Pfeiffer for the GWA14 conference

This talk will introduce the Spectral Einstein Code, a general relativistic code to solve the inspiral and merger of two black holes. I will give an update on numerical results with SpEC, and will discuss several applications of the simulations, among them the construction of waveform models within the effective-one-body formalism, the study of gravitational self-force effects through comparable-mass binary black hole simulations, and a comparison of the post-Newtonian precession dynamics with numerical simulations.
Thu, 2014-12-04 09:00(Rosensäle)
Gravitational waves from coalescing neutron star binaries
From Masaru Shibata for the GWA14 conference

Wed, 2014-12-03 10:00(Rosensäle)
Post-merger Oscillations in Binary Neutron Star Mergers
from Nikolaos Stergioulas for the GWA14 conference

Because of the recent discovery of two-solar-mass neutron stars, the equation of state of high density matter is likely to be sufficiently stiff to allow for a long-lived remnant, when two neutron stars merge. The merger excites a number of oscillation modes, having large (nonlinear) amplitude, that are interesting as gravitational waves sources for second- and third-generation interferometric detectors. Apart from a dominant linear oscillation mode, additional nonlinear contributions appear. I discuss the main properties of these oscillations as well as the prospects of constraining the mass and radius (and thus the equation of state) with future detections.
Wed, 2014-12-03 09:00(Rosensäle)
Searching for gravitational waves from the early Universe
from Fabian Schmidt for the GWA14 conference

Tue, 2014-12-02 11:30(Rosensäle)
Gravitational wave detection using squeezed light
from Roman Schnabel for the GWA14 Conference

Current gravitational wave (GW) detectors are Michelson-type kilometre-scale laser interferometers measuring the distance changes between in vacuum suspended mirrors. The sensitivity of these detectors is limited by quantum noise of the laser light. Since 2010, GEO600 has been using so-called nonclassical light that has a ‘squeezed’ quantum noise, and it has been demonstrated that squeezed light is able to increase the GW detector sensitivity at shot-noise limited frequencies. In future, squeezed light might be used to further improve the sensitivity of GW detectors, then also at radiation pressure noise dominated frequencies and at frequencies where photon-phonon scattering is limiting the detectors performance.
Tue, 2014-12-02 10:00
Gravitational waves from black-hole binaries
from Mark Hannam for the GWA14 Conference
Tue, 2014-12-02 09:00
Progress in Three-dimensional Supernova Modeling
from Hans-Thomas Janka for the GWA14 conference

3D supernova simulations have become possible only very recently and have already led to the discovery of novel and unexpected phenomena, although they still need to confirm the basic theoretical concepts of the explosion mechanism. The talk will review the status of 3D modeling and interesting new perspectives to probe the supernova core dynamics by neutrinos and gravitational waves measured in the case of a next galactic event.
Mon, 2014-12-01 19:00(Max-Wien-Platz 1, Lecture Hall 1)
Gravitationswellenastronomie: Bald Neues von der dunklen Seite des Universums!
Public Talk of the GWA14 Conference from Karsten Danzmann

Können wir das Universum hören? Auf den ersten Blick ist das eine unsinnige Frage, denn natürlich gibt es im Weltall keine Luft, in der sich der Schall ausbreiten könnte. Wenn aber un­sere Ohren nur empfindlich genug wären, dann könn­ten sie auf eine besondere Art von Wellen reagieren: auf Gravitationswellen! Vor mehr als 90 Jahren sagte Al­bert Einstein die Existenz von Gravitationswellen als Konsequenz seiner allgemeinen Relativitätstheorie vor­aus. Gravitationswellen sind winzige Verbiegungen des Raumes und der Zeit, die von schnellbewegten, großen Massen erzeugt werden und sich mit Lichtgeschwindig­keit wellenförmig ausbreiten. Sie wurden noch nie di­rekt nachgewiesen. Mehrere laserinterferometrische Gravitationswellendetektoren mit Armlängen von Ki­lometern werden gegenwärtig auf der Erde betrieben, um Gravitationswel­len zu erforschen, darunter auch GEO600 in der Nähe von Hannover. Bald folgen Detektoren im Weltraum mit Millionen km Armlänge, insbesondere die Satelliten-Mission LISA. Ausgangspunkt für diese geheimnis­vollen Wellen könnten z. B. verschmelzende Doppel­sterne, Neutronensterne, Supernovae, Schwarze Löcher und der Urknall sein. Ihre Beobachtung erfordert modernste Lasertechnologie und Messungen an der quantenmechanischen Nachweisgrenze.
Mon, 2014-12-01 15:00(Rosensäle)
Beyond the second generation of gravitational wave detectors
from Ronny Nawrodt for the GWA14 Conference

Gravitational wave detectors are currently upgraded to the 2nd generation achieving extremely high sensitivities in a wide frequency band. A first direct detection of gravitational waves is expected once these instruments are getting online. Such a detection will mark the starting point for a gravitational wave based astronomy. Thus, detectors of the third generation are designed to be used as efficient astronomical observatories. For this purpose the sensitivity of the 2nd generation detectors has to be enhanced. As the sensitivity of current instruments approaches the thermal noise floor of their fused silica components a radical change of materials is necessary. Additionally, 3rd generation detectors will be operated at cryogenic temperatures to further reduce thermal noise and increase their sensitivity. This talk will give an overview of proposed technologies towards 3rd generation detectors leading to a 10 times higher sensitivity throughout the audio band. The focus will lie on the selection of materials for the optics as well as the suspension elements according to their properties. The characterisation of these materials and the choice of their operational temperature is discussed as well.
Mon, 2014-12-01 14:00
From the beginning to the second generation of gravitational wave detectors
from David Shoemaker for the GWA 2014 Conference

A brief history of gravitational wave detection using laser interferometers will be given, followed by a status report on one example of the second generation of detectors, Advanced LIGO.
Tue, 2014-11-25 16:00(SR 5, Helmholtzweg 4)
Dark energy and the uniqueness of general relativity
Prof. Matthias Bartelmann
Ruprecht-Karls-Universität Heidelberg
Thu, 2014-11-20 14:15
Hamiltonian approach to QCD in Coulomb gauge: From the vacuum to finite temperatures
Prof. Dr. Hugo Reinhardt, Universität Tübingen
Wed, 2014-11-19 16:15(HS 2, Abbeanum)
Lightfront quantisation and strong field QED
Greger Torgrimsson (Chalmers)
Fri, 2014-11-14 16:00(HS 2, Abbeanum)
Ab Initio Simulationen zur Struktur und Dynamik warmer dichter Aluminiumplasmen
Hannes Rüter, MSc,
Universität Rostock
Thu, 2014-11-13 14:15
Non-Equilibrium Dynamics of a Holographic Superfluid
Andreas Samberg,
Ruprecht-Karls-Universität Heidelberg
Thu, 2014-11-06 14:15
Can effects of quantum gravity be observed in the CMB?
Prof. Claus Kiefer, University Cologne
Tue, 2014-11-04 16:15(SR 5, Helmholtzweg 4)
Supersymmetric Yang Mills Theories
Dr. Georg Bergner, Universität Bern
Tue, 2014-10-28 16:15(SR 5, Helmholtzweg 4)
Coupling constant metamorphosis and conformally covariant Laplacians
Dr. Jonathan Kress (University of New South Wales, Sydney)






Calendar


January 2015
Su Mo Tu We Th Fr Sa
28 29 30 31 01 02 03
04 05 06 07 08 09 10
11 12 13 14 15 16 17
18 19 20 21 22 23 24
25 26 27 28 29 30 31
01 02 03 04 05 06 07

Upcoming Events

2015-02-11 16:15
tba