Events
Biological and soft-matter physics
Electrolubrication in flowing liquid mixtures
Prof. Yoav Tsori
Dept of Chemical Engineering, BGU
Thu, 27 Jun 2024, 12:10
Sacta-Rashi Building for Physics (54), room 207
Abstract: We describe the “electrolubrication” occurring in liquid mixtures confined between charged surfaces. For a mixture of two liquids, the effective viscosity decreases markedly in the presence of a field. The origin of this reduction is field-induced phase separation, leading to the formation of two low-viscosity lubrication layers at the surfaces. The thickness of the lubrication layers depends on the Debye length and the mixture correlation length. These layers facilitate larger strain at a given stress. The effect is strong if the viscosities of the two liquids are sufficiently different, the volume fraction of the less viscous liquid is small, the gap between the surfaces is small, and the applied potential is large. The maximum liquid velocity and flux are increased a factor α. In most liquids, α ∼ 1 – 10, and in mixtures of water and glycerol α ∼ 80 – 100 under relatively small potentials.
Particles and Fields Seminar
Probing Confinement in Anti-de Sitter Space
Riccardo Ciccone
University of Haifa
Mon, 01 Jul 2024, 14:00
Sacta-Rashi Building for Physics (54), room 207
Abstract: Anti-de Sitter space acts as an infra-red cutoff for asymptotically free theories, allowing interpolation between a weakly-coupled small-sized regime and a strongly-coupled flat-space regime. I will discuss this interpolation in the context of Yang-Mills theories in AdS from the perspective of boundary conformal theories and its implications for the confinement/deconfinement transition. We find indications that at the transition a singlet scalar operator becomes marginal, destabilizing the deconfined phase existing at a small size and triggering a boundary renormalization group flow to a gapped, confined phase that smoothly connects to flat space. Based on forthcoming work with F. De Cesare, L. Di Pietro, M. Serone.
Physics Colloquium
Unraveling the Mysteries of Tidal Disruption Events
Prof. Assaf Horesh
Hebrew University
Tue, 02 Jul 2024, 15:15
Ilse Katz Institute for Nanoscale Science & Technology (51), room 015
Abstract: Tidal Disruption Events (TDEs) are cosmic occurrences where a star is torn apart by the immense gravitational forces of a supermassive black hole. This field is one of the key focus of contemporary astrophysical time-domain research, which offers critical insights into the nature of black holes, the dynamics of stellar destruction, and accretion physics. In my talk I will review our current understating of TDEs, and will address some challenges and pressing questions in the field. I will present new recent discoveries such as the (highly debated) association of neutrinos with TDEs, and my own discovery of delayed radio flares. The latter phenomenon shows that radio emission from TDEs can turn on sometimes months, and even years after stellar disruption. While we identified some possible explanations, the nature of these flares still remains mostly unknown. I will conclude by discussing future avenues in TDE research.
Physics Colloquium
TBA
Dr. Andrea Caputo
CERN
Tue, 09 Jul 2024, 15:15
Ilse Katz Institute for Nanoscale Science & Technology (51), room 015
Abstract:
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