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Calendar of Physics Talks Vienna
| Speaker: | Sean HARTNOLL (Cambridge University) |
| Abstract: | The IKKT model is a large N matrix integral that arises in string theory as the worldvolume theory of N D-instantons. It holds the promise of being a uniquely tractable model of holographic duality, but has some important differences with other better-understood cases, notably the absence of a time and the related absence of a "decoupling limitâ in which the theory is obtained as an isolated sub-sector of string theory. I will discuss a supersymmetric deformation of the IKKT model that may improve the situation by introducing a dimensionless coupling constant.
Supersymmetric localisation allows the model to be greatly simplified. I will discuss the phase diagram of the model, which exhibits a phase transition between two limits, and the sense in which the model leads to an emergent spacetime. |
| Date: | Tue, 24.06.2025 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Kurt-Goedel Lecture Hall, 1090 Vienna, Boltzmanngasse 5, ground floor |
| Contact: | S. Fredenhagen, M. Sperling |
| Casimir interaction of Dirac materials. A QFT perspective. [Theory colloquium] |
| Speaker: | Dmitri Vassilevich (ABC Federal U.) |
| Abstract: | In some novel materials (graphene, topological insulators, Weyl semimetals, etc.), the dispersion relation of quasiparticles is (approximately) given by the Dirac equation. Thus, it is natural to use the methods of Quantum Field Theory (QFT) in the description of various quantum phenomena. Here we focus on (i) the Casimir interaction of graphene, (ii) the possibility of Casimir repulsion between Chern-Simons materials. At the end, the reasons for the effectiveness of the QFT description will be discussed. |
| Date: | Wed, 25.06.2025 |
| Time: | 14:15 |
| Duration: | 60 min |
| Location: | FH HS 4, TU Wien, Wiedner Hauptstr. 8, Freihaus, yellow area, 2nd floor |
| Contact: | Daniel Grumiller |
| Levitated diamond particles for spin-levitodynamics experiments |
| Speaker: | Simon Baier, PhD (University of Innsbruck) |
| Abstract: | Are the laws of quantum physics applicable to macroscopic objects of any size? This overarching question lies at the heart of current research, which aims to provide deep insights into the nature of quantum mechanics, enable the creation of delocalized superposition states of massive objects, and develop techniques to push the boundary between the quantum and classical realms.
At the University of Innsbruck, we are addressing this question by employing levitated particles in well-isolated environments. We levitate nanoparticles in Paul traps and control their external motion using feedback cooling techniques. In this seminar, I will focus on our recent efforts with levitated diamond particles that host Nitrogen-Vacancy (NV) center spin states. Diamond levitation can allow for coherent coupling between the particleâs external motion and the spin state of a single NV center embedded in the |
| Date: | Thu, 26.06.2025 |
| Time: | 13:30 |
| Duration: | 45 min |
| Location: | Freihaus, Sem. Room yelloe 7th floor |
| Contact: | carlos.gonzalez-ballestero@tuwien.ac.at |
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