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Calendar of Physics Talks Vienna
| Canonical Quantization of Singular Spaces: Symmetry Reduction, Mass Gap Bounds, and Non-smooth Calculus (Vienna Theory Lunch Seminar) |
| Speaker: | Luca Mrini (University of Vienna) |
| Abstract: | We study the canonical quantization of singular configuration spaces and identify natural generalizations of the core structures of quantum mechanics. In this way, we propose new tools to probe non-perturbative quantum properties of singular systems, including those arising from symmetry constraints and gauge theories. Under minimal assumptions, we construct a Hilbert space of quantum states, generalized position and momentum operators, a kinetic-plus-potential Hamiltonian, and unitary quantum dynamics for such systems. Our main result is a new technique to bound the mass gap of certain singular systems obtained via symplectic reduction by analyzing the curvature of the non-reduced configuration space. [[part of the "Vienna Theory Lunch Seminar, see https://lunch-seminar.univie.ac.at ]] |
| Date: | Tue, 04.11.2025 |
| Time: | 12:15 |
| Duration: | 75 min |
| Location: | TU Wien: Wiedner Hauptstr. 8-10, green area, 5th floor, seminar room DA05E10 |
| Contact: | Luciano Montecchio |
| What if phi^4 theory in 4 dimensions is non-trivial in the continuum? |
| Speaker: | Paul ROMATSCHKE (TU Vienna) |
| Abstract: | Traditionally, scalar phi^4 theory in four dimensions is thought to be quantum trivial in the continuum. In this talk, I critically review what quantum triviality is, and in particular which parts of the idea have actually been mathematically proved as opposed to just assumed to be true. I go on to exploit loopholes in the mathematical proofs, notably multi-component fields, to present a concrete calculation that avoids quantum triviality in scalar phi4 theory in the continuum. There is a price to pay to avoid triviality, but there are also potentially rich rewards. Your mileage will vary. Whatever the outcome, it is great fun to work on this subject! |
| Date: | Tue, 04.11.2025 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-Lecture Hall, 1090 Vienna, Boltzmanngasse 5, 5th floor |
| Contact: | S. Fredenhagen, M. Sperling |
| q-Desics - Particle motion in quantum gravity |
| Speaker: | Benjamin Koch (TU Wien) |
| Abstract: | We revisit the motion of test particles in quantum-gravitational backgrounds by introducing the concept of q–desics, quantum-corrected analogs of classical geodesics. Unlike standard approaches that rely solely on the expectation value of the spacetime metric, this formulation is based on the expectation value of quantum operators, such as the affine connection operator. This allows to capture richer (quantum)-geometric information. Exemplary results include lightlike radial motion and circular motion with quantum gravitational corrections far above the Planck scale. This framework provides a refined description of motion in quantum spacetimes and opens new directions for probing the interface between quantum gravity and classical general relativity.
Note: ArXiv paperpitch: https://youtu.be/sf3A2qnE3F4,
Live on YouTube: https://www.youtube.com/c/IQOQIVienna |
| Date: | Tue, 04.11.2025 |
| Time: | 15:30 |
| Duration: | 45 min |
| Location: | Boltzmanngasse 3, 2nd floor, 1090 Vienna |
| Contact: | Hosted by: Caslav Brukner |
| Building spintronic neural networks with radio-frequency connectivity |
| Speaker: | Dédalo Sanz Hernandez (Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, FRANCE ) |
| Abstract: | Spintronics brings intrinsic memory, wave-based dynamics, and non-linearity into neuromorphic computing, offering a promising route toward energy-efficient, brain-inspired hardware. In this work, we experimentally demonstrate a compact neural network in which all computing elements—both synapses and neurons—are implemented using magnetic tunnel junctions (MTJs).
The architecture uses frequency multiplexing to interconnect neurons and synapses: each junction's oscillation frequency serves as a unique address, enabling selective coupling between elements sharing the same frequency. I will present two implementations of this architecture, each highlighting different advantages.
In the first approach, binary vortex-based synapses can be remotely switched between states without requiring direct local access. This is achieved by globally broadcasting RF signals, allowing highly efficient con |
| Date: | Tue, 04.11.2025 |
| Time: | 16:00 |
| Location: | TU Wien, Institut für Angewandte Physik, E134 1040 Wien, Wiedner Hauptstraße 8-10 Yellow Tower „B“, 5th floor, SEM.R. DB gelb 05 B |
| Contact: | Prof. A. Fernández-Pacheco |
| Toponium at the LHC: a new frontier in top-quark physics |
| Speaker: | Benjamin FUKS (LPTHE, Sorbonne Université) |
| Abstract: | The top quark, the heaviest known elementary particle, has long been thought unable to form bound states. However, intriguing hints in recent LHC data suggest that toponium, a short-lived quasi-bound state of a top-antitop pair, might have left observable traces in data and possibly even been discovered.
In this talk, I will discuss why toponium is such a unique laboratory for studying the theory of the strong interaction in the non-relativistic regime, how modern techniques allow us to incorporate bound-state effects into state-of-the-art collider simulations, and what experimental signatures could reveal the presence of toponium in current and future LHC data. I will finally highlight recent results, ongoing searches and the exciting prospects for using toponium as a new window into the physics of the top quark. |
| Date: | Tue, 04.11.2025 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Erwin-Schroedinger-Lecture Hall, 1090 Vienna, Boltzmanngasse 5, 5th floor |
| Contact: | A. Hoang, M. Procura |
| ESI Medal 2025 Award Ceremony |
| Speaker: | Georg Kresse, Mariana Rossi, Giuseppe Foffi, Michele Parrinello (U of Vienna, MPI Hamburg, U of Paris-Saclay, ETH Zurich and Istituto Italiano di Tecnologia in Genova) |
| Abstract: | Prof. Michele Parrinello (ETH Zurich and Istituto Italiano di Tecnologia in Genova) is honored for his seminal contributions to computational science, particularly through the development of groundbreaking algorithms that have opened new frontiers in soft matter, biological, and condensed matter physics, as well as for applying these methods to solve important open problems. Among his most recent achievements are the advancement of metadynamics sampling techniques, which have revolutionized the study of complex free-energy landscapes — including those associated with protein conformational changes — and the pioneering integration of machine learning with molecular dynamics, a transformative leap that is redefining the frontiers of numerical simulations. He is also recognized for his efforts in promoting promoting transparency and reproducibility in computational science. |
| Date: | Fri, 07.11.2025 |
| Time: | 14:00 |
| Duration: | 240 min |
| Location: | Erwin Schrödinger Institute, Boltzmann Lecture Hall, Boltzmanngasse 9, 1090 Wien |
| Contact: | secr@esi.ac.at, https://www.esi.ac.at/events/e593/ |
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