
Calendar of Physics Talks Vienna
Asymptotic symmetries in Carrollian theories of gravity 
Speaker:  Alfredo Perez (CECS, Valdivia) 
Abstract:  In this talk, asymptotic symmetries in Carrollian gravitational theories in 3+1 space and time dimensions obtained from “magnetic” and “electric” ultrarelativistic contractions of General Relativity are analyzed. In both cases, parity conditions are needed to guarantee a finite symplectic term, in analogy with Einstein gravity. In particular, it is shown that from the point of view of the asymptotic symmetries, the magnetic contraction can be seen as a smooth limit of General Relativity, in contrast to its electric counterpart. 
Date:  Tue, 18.01.2022 
Time:  14:00 
Duration:  60 min 
Location:  Zoom https://tuwien.zoom.us/j/95423793232?pwd=OEhvemhuaUcvbTVYS0gwV3F3amNidz09 ID de réunion : 954 2379 3232 Mot de passe : Gya7QquF 
Contact:  D. Grumiller, S. Fredenhagen, E. Battista, R. Ruzziconi 
Semiclassically propagating states of quantum clocks are not Gaussian — how and why 
Speaker:  Magdalena Zych (ARC Centre for Engineered Quantum Systems), Queensland 
Abstract:  In quantum physics an ideal clock can be modelled as a composite particle whose internal states ‘measure' proper time along the the particle's trajectory. However,quantum particles do do not follow classical trajectories due to Heisenberg Uncertainty Principle(HUP)for position and momentum.A question then arises what are the states of quantum clocks that follow semiclassical paths?In textbooks quantum mechanics,semiclassical states of quantum particles are the wellknown Gaussian states derived from minimising the HUP.I will show that for quantum clocks semiclassically propagating states are not Gaussian but a new class of quantum states that are derived from a new uncertainty inequality — for configuration space rather than for phase space variables.I will also discuss some key properties of these states such as the inherent nonseparability of their internal and external degrees ... 
Date:  Thu, 20.01.2022 
Time:  11:00 
Duration:  60 min 
Location:  zoom.us/j/6540036841?pwd=SytyVkZJZzNyRG9lMm13ejlHeHRRUT09 Meeting ID: 654 003 6841 Passcode: Gs4brS 
Contact:  P. Chrusciel, D. Fajman 
