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Monday, April 29th 2019

12:15 pm:

Tuesday, April 30th 2019

4:00 pm:

Wednesday, May 1st 2019

1:25 pm:

A collection of coupled linear oscillators is widely regarded as a trivial physical system. Nevertheless, in recent years it has become evident that weak loss (or gain) in these systems can result in a variety of qualitative surprises - even in the purely linear regime. Effects that have attracted considerable attention include: PT symmetry breaking, exceptional points, non reciprocity, and topological control. I will describe a simple framework that unites these "non-Hermitian" effects and explains why topology emerges generically in damped coupled linear oscillators. I will discuss the application of these concepts in classical systems and in quantum systems. Lastly, I will describe an optomechanical experiment that offers a natural way to realize generic non-Hermiticity.

Thursday, May 2nd 2019

10:10 am:

12:10 pm:

3:35 pm:

To observe quantum effects in the motion of macroscopic objects typically requires high-precision readout, low temperature, and low optical and mechanical loss. Superfluid helium offers many advantages in these regards. I will describe two optomechanics experiments based on superfluid helium. In the first, the superfluid fills a Fabry-Perot optical cavity. The cavity is used to monitor the quantum fluctuations of the superfluid's acoustic modes. This system is amenable to single photon/phonon detection schemes, and so may provide a route to more exotic quantum effects in massive objects. The second experiment uses magnetic levitation to suspend a mm-scale drop of superfluid in vacuum. I will describe preliminary measurements of the drop's formation, trapping, and evaporative cooling, and of the drop's mechanical resonances and optical resonances.

4:00 pm:

Friday, May 3rd 2019

11:00 am:

The rapid neutron capture process (r process) is responsible for the production of half of the elements heavier than iron that we observe in the Universe. The quest to identify its actual astrophysical site is still ongoing, but there are strong indications, including the recent observation of the GW170817 electromagnetic counterpart, that make neutron star mergers (NSM) a likely candidate. Reliable estimates of nucleosynthesis yields on NSM require an accurate description of the relevant nuclear physics inputs including nuclear masses, neutron capture rates, β- and α-decay rates and, for ﬁssioning nuclei, ﬁssion rates and ﬁssion fragments distributions. Several of these quantities can be computed from a consistent theoretical framework using the energy density functional (EDF) approach.

In this talk I will revise how uncertainties in the nuclear physics properties of neutron-rich nuclei impact nucleosynthesis calculations, with a focus in the ﬁssion properties of (super)heavy nuclei. I will present a new set of ﬁssion rates obtained from microscopic nuclear many-body calculations, which are used as a nuclear input in r-process nucleosynthesis calculations in NSM. The possible formation of superheavy elements during the r-process nucleosynthesis as well as the impact on kilonova light curve, a quasithermal transient powered by freshly synthesized r-process nuclei, will be discussed. Finally, I will introduce recent developments in the estimation of ﬁssion yields and the possible extension to r-process nuclei.

12:20 pm:

12:30 pm:

2:30 pm:

4:00 pm:

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