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Calendar of Physics Talks Vienna
| Speaker: | Severin Lüst (Harvard) |
| Abstract: | I will discuss string theory compactifications where a large number of moduli is stabilized by fluxes. I will present a conjecture which rules out the stabilization of all complex-structure moduli in F-theory at a generic point in moduli space by fluxes that satisfy the tadpole cancellation condition. Evidence for this conjecture comes from K3xK3 compactifications. Using evolutionary algorithms we found that moduli stabilization needs fluxes whose charge is slightly smaller than 1/2 of the number of moduli and larger than what is allowed by tadpole cancellation. I will furthermore comment on possible implications on de Sitter vacua obtained by antibrane uplift in long warped throats. |
| Date: | Tue, 15.12.2020 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | https://moodle.univie.ac.at/mod/bigbluebuttonbn/guestlink.php?gid=x8o6ILSKJuC9 |
| Contact: | Céline Zwikel |
| Quantum Simulation of 2D Antiferromagnets with programmable, 196-atom Rydberg arrays |
| Speaker: | Michael Schuler (TU Wien) |
| Abstract: | Quantum simulation using synthetic systems is a promising route to solve outstanding quantum many-body problems in regimes where other approaches fail. In this talk I will present a recent quantum simulationof the iconic antiferromagnetic transverse-field Ising model, achieved on a programmable Rydberg quantum simulator, which was pushed to an unprecedented regime with up to 196 atoms.I will demonstrate the high fidelity and versatility of this platform by showing that it can prepare antiferromagnetic states on different geometries, in particular square and frustrated triangular arrays. The quantum simulations are certified by extensive numerical calculations using matrix product states up to the computationally feasible size of ~100 particles. We demonstrate an excellent agreement when experimental imperfections are properly taken into account. Finally, we unveil a potential advantage o |
| Date: | Wed, 16.12.2020 |
| Time: | 14:15 |
| Duration: | 45 min |
| Location: | on-line |
| Contact: | Peter Rabl |
| A new spinorial approach to mass inequalities for black holes in General Relativity |
| Speaker: | Juan A. Valiente Kroon (Queen Mary, University of London) |
| Abstract: | In this talk I will discuss a new spinorial strategy for the construction of geometric inequalities involving the ADM mass of black hole systems in General Relativity.This approach is based on a second order elliptic equation(the approximate twistor equation)for a valence 1 Weyl spinor.This has the advantage over other spinorial approaches to the construction of geometric inequalities based on the Sen-Witten-Dirac equation that it allows to specify boundary conditions for the two components of the spinor.This greater control on the boundary data has the potential of giving rise to new geometric inequalities involving the mass. In particular I will show that the mass is bounded from below by an integral functional over a marginally outer trapped surface(MOTS)which depends on a freely specifiable valence 1 spinor. From this main inequality by choosing the free data in an appropriate way... |
| Date: | Thu, 17.12.2020 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | zoom - https://zoom.us/j/92376135485?pwd=LzlUemhvcU5rL0hhZGxPOUVieDgxZz09 |
| Contact: | Piotr Chrusciel, David Fajman |
| De Sitter vacua from anti-D3-branes in type IIB LVS compactifications |
| Speaker: | Roberto Valandro (Trieste U. and INFN Trieste) |
| Abstract: | We will begin with an introduction on moduli stabilisation in type IIB compactifications on CY orientifolds, with de Sitter uplift due to an anti-D3 brane. We consider a concrete setup where an anti D3-brane sits at the tip of a warped throat and the stabilised volume is exponentially large as in the large volume scenario (LVS). We analyse the conditions on the parameters of the EFT such that they are in the region of validity. We illustrate our results with an explicit choice of Calabi-Yau manifold and D-brane configuration, where moduli stabilisation gives rise to a de Sitter minimum. |
| Date: | Thu, 17.12.2020 |
| Time: | 16:30 |
| Duration: | 60 min |
| Location: | https://tuwien.zoom.us/j/95482849369?pwd=SkU2WU5hMVJBQWsyVlFXRlRvQlIvdz09 |
| Contact: | Laura Donnay, Niccolo Cribiori |
| qBounce: current developments in the determination of gravitational levels of UCNs using GRS |
| Speaker: | Jakob Micko ( Institut Laue-Langevin, Grenoble) |
| Abstract: | The search for "Dark Energy" has been a driving force for fundamental physics in the last decades. Attempts to observe effects in earth based experiments have thus far only led to limitations of the available parameter space of dark energy models. I will describe the qBounce experiment that uses Gravity Resonance Spectroscopy (GRS) to investigate gravitationally bound states of neutrons. Neutrons are used as uncharged massive particles representing ideal test masses to investigate gravity. Possible extensions of the Standard Model introducing dark energy models directly change the result of the experiment, enabling us to set constraints on the parameters of such interactions. |
| Date: | Fri, 18.12.2020 |
| Time: | 10:00 |
| Duration: | 45 min |
| Location: | on-line |
| Contact: | Hartmut Abele |
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