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Calendar of Physics Talks Vienna
| Elements of Celestial Conformal Field Theory |
| Speaker: | Stephan Stieberger (Max Planck Institute, Munich) |
| Abstract: | I will introduce into subject of holographic description of four-dimensional massless physics
as conformal field theory on the celestial sphere and report on progress on celestial conformal field theory (CCFT).
In celestial holography, four-dimensional scattering amplitudes are considered as two-dimensional conformal correlators of a putative two-dimensional CCFT. The simplest way of converting momentum space amplitudes into CCFT correlators is by taking their Mellin transforms with respect to light-cone energies. For massless particles, like gluons, however, such a construction leads to three-point and four-point correlators that vanish everywhere except for a measure zero hypersurface of celestial coordinates. This is due to the four-dimensional momentum conservation law that constrains the insertion points of the operators associated with massless particles [...] |
| Date: | Tue, 24.01.2023 |
| Time: | 14:00 |
| Duration: | 60 min |
| Location: | Erwin-Schrödinger-Hörsaal (University of Vienna, Boltzmanngasse 5, 5th floor, Room Nr. 3500) |
| Contact: | D. Grumiller, S. Fredenhagen, E. Battista, R. Ruzziconi |
| An MCMC Revision of the Universal Texture Zero of Flavor |
| Speaker: | Ronald James Talbert Jr. (Cambridge) |
| Abstract: | In this talk I plan to address an old problem of particle physics (the flavor puzzle) with an aging solution(a broken non-Abelian discrete symmetry),albeit with a rather novel phenomenological technique:a simple Markov Chain Monte Carlo (MCMC) algorithm. Indeed the âUniversal Texture Zeroâ (UTZ) effective theory I co-authored in 2017 was argued to successfully resolve the mass, mixing,and CP-violating structure of both the quark and lepton flavor sectors of the Standard Model with as few as nine infrared model parameters, and in a manner consistent with ultraviolet Grand Unification. However, the original 2017 numerical analysis was insufficient to exhaustively explore even this minimal parameter space, much less that of the augmented next-to-leading order (NLO) UTZ effective Lagrangian,and was not capable (e.g.)of making robust predictions for the leptonic Dirac CP-violating phase .... |
| Date: | Tue, 24.01.2023 |
| Time: | 16:15 |
| Duration: | 60 min |
| Location: | Fakultaet fuer Physik, Erwin Schroedinger-HS, Boltzmanngasse 5, 5. Stock |
| Contact: | A. Hoang, M. Procura, T. Corbett |
| Gluing small black holes into initial data sets |
| Speaker: | Peter Hintz (ETH Zuerich) |
| Abstract: | We describe a localized gluing result for the constraint equations in which a small mass rescaling of an asymptotically flat data set is glued into the neighborhood of a point inside of another data set.
As the smallness parameter tends to zero, rescalings of normal coordinates around the point become asymptotically flat coordinates on the asymptotically flat data set.
As an application, we construct initial data for the Einstein vacuum equations which conjecturally evolve into extreme mass ratio inspirals. |
| Date: | Thu, 26.01.2023 |
| Time: | 15:30 |
| Duration: | 60 min |
| Location: | via ZOOM https://univienna.zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09 |
| Contact: | P. Chrusciel, D. Fajman |
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