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Calendar of Physics Talks Vienna
| Classification of Minimal Unitary 3d N=4 Coulomb Branches - CANCELLED! |
| Speaker: | Sinan MOURA SOYSÃÂREN (University of Vienna) |
| Abstract: | Obtaining the classification of 3d N=4 quiver theories whose Coulomb Branches have an isolated symplectic singularity is an essential step in understanding moduli spaces of vacua of supersymmetric theories with 8 supercharges in any dimensions. Using the Decay and Fission algorithm, the complete list of such unitary quiver theories can be derived, reproducing known results and giving rise to previously unknown families. |
| Date: | Tue, 06.05.2025 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger Lecture Hall, 1090 Vienna, Boltzmanngasse 5, 5th floor |
| Contact: | S. Fredenhagen, M. Sperling |
| A panoramic view of low dimensional manifolds |
| Speaker: | Willi Kepplinger (University of Vienna) |
| Abstract: | The character and status of very simple sounding questions in manifold theory depends crucially on the dimension of the manifold. An illustrative example is the famous Jordan curve theorem which roughly speaking states that a topological embedding of S^1 into R^2 separates R^2 into a bounded component (which is homeomorphic to a disk) and an unbounded one. Naively speaking this theorem seems obvious, if annoying to prove. In reality, it is a miracle it is true in the first place as corresponding statements in dimension 3 and higher are simply wrong. In this talk I will try to give an overview over questions in low dimensional topology (such as existence and uniques of smooth structures, classification of manifolds) and how these depend on the dimension. |
| Date: | Wed, 07.05.2025 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | Seminarraum A, Waehringer StraÃe 17, 1090 Vienna, 2nd floor |
| Contact: | D. Fajman |
| Generalised Fluid Dynamics |
| Speaker: | Jacopo de Nardis (LPTM - Cergy Paris Université) |
| Abstract: | I will present the theory of generalised hydrodynamics, and its discretisation in terms of gases of interacting wave packets, which applies to integrable systems in 1+1D (both quantum and classical) and quasi-integrable under external perturbations (external trapping potentials or non-integrable inter-particle potentials).
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| Date: | Wed, 07.05.2025 |
| Time: | 15:00 |
| Duration: | 45 min |
| Location: | Seminar room ZE 01-1, ATI |
| Contact: | Frederik Møller |
| Fundamental Limits of Nanophotonic Design |
| Speaker: | Zeyu Kuang (TU Wien) |
| Abstract: | Nanoscale fabrication techniques, computational inverse design, and fields from silicon photonics to metasurface optics are enabling transformative use of an unprecedented number of structural degrees of freedom in nanophotonics. A critical need is to understand the extreme limits to what is possible by engineering nanophotonic structures. I will discuss the first general theoretical framework identifying fundamental limits to lightâmatter interactions, and show limits in applications across nanophotonics, including far-field scattering, perfect absorption, and arbitrary mode coupling. I will show how to derive those limits from the basic laws of power conservation, which every device has to satisfy. This method offers a new way to understand optimal designs and their fundamental limits, in nanophotonics and beyond. |
| Date: | Wed, 07.05.2025 |
| Time: | 16:15 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Stefan Rotter |
| Speaker: | Gerhard Rempe (MPQ) |
| Abstract: | Entanglement is a genuine quantum physics concept that has so far mostly been studied with only a few qubits. However, generating customised multi-qubit entanglement is a formidable challenge, especially in distributed quantum networks. The talk will present a unique approach to generate a zoo of almost arbitrary entanglement topologies described by graphs. These open the door to a multi-node quantum internet, a measurement-based quantum computer and a one-way quantum repeater. |
| Date: | Fri, 09.05.2025 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Helmut Rauch Hörsaal ATI |
| Contact: | Franz von Silva-Tarouca |
| Building a dysprosium tweezer experiment to study collective light-scattering |
| Speaker: | Damien Bloch (Institut dâOptique ) |
| Abstract: | Dissipative quantum many-body problems, such as those arising we considering collective spontaneous emission in atomic ensembles, present theoretical challenges. During my PhD, we have developed a setup to experimentally study these effects on ordered ensembles of atoms.
For this, we realised the first trapping and imaging of single dysprosium atoms in optical tweezers. To do so, we measured the dynamical polarizabilities of dysprosium at 532 nm and showed the existence of a magic tweezer polarization that makes high fidelity imaging of single atoms possible.
Leveraging the rich internal structure of dysprosium, we were then able to measure the atoms' internal states on an optical transition with microsecond lifetime. We used this technique to investigate collective light scattering in chains of dysprosium atoms. We studied the frequency shift, also called cooperative Lamb shift, result |
| Date: | Fri, 09.05.2025 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | Bibliothek Atominstitut |
| Contact: | Julian Léonard |
| Gauge Invariance and Particles |
| Speaker: | Axel MAAS (University of Graz) |
| Abstract: | On a formal, fundamental level in a non-Abelian gauge theory only composite fields can be gauge-invariant, rather than the elementary fields employed in perturbation theory. While at first sight in contradiction to the phenomenological success of perturbation theory in electroweak physics, there is a deeper reason for both being compatible, the Fröhlich-Morchio-Strocchi mechanism. Its working and validity has been demonstrated explicitly in lattice simulations. However, even then this leaves still room for new phenomena in the standard model. Moreover, the standard model is special. Beyond the standard model these issues yield qualitative changes and affect such varied scenarios like grand-unified theories, supersymmetry, and quantum gravity. The talk provides an overview of the underlying mechanisms and finally highlights a few example applications. |
| Date: | Fri, 09.05.2025 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Ernst Mach Lecture Hall, 1090 Vienna, Boltzmanngasse 5, 2nd floor |
| Contact: | A. Hoang, M. Procura |
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