TheoryLab

If you missed Matteo’s lectures on liquids dynamics you can see them here:

Matteo will give a series of lectures next week about the theory of liquids dynamics @ the Institute of Continuous Media Mechanics of the Ural Branch of the Russian Academy of Science (ICMM UB RAS) Perm, Russia. The details are below.

Program:

16 ноября 2021
11:00 (9:00 МСК, 14:00 Shanghai)
Лекция 2 – Prof. M.Baggioli: The dynamics of (k-gapped) shear waves and their dispersion relation

17 ноября 2021
11:00 (9:00 МСК, 14:00 Shanghai)
Лекция 4 – Prof. M.Baggioli: The low frequency scaling of the vibrational density of states

19 ноября 2021
11:00 (9:00 МСК, 14:00 Shanghai)
Лекция 6 – Prof. M.Baggioli: The temperature dependence of the heat capacity.

Abstract. The vibrational, thermodynamically and mechanical properties of solids are well-understood since Debye’s work in 1912. On the contrary, the same understanding for amorphous systems (liquids and glasses) has remained elusive for more than a century and it is still a mystery. In these lectures, we will consider three distinctive properties of liquids which are drastically different from their solid counterpart and which remain largely unexplained: (I) the dynamics of (k-gapped) shear waves and their dispersion relation, (II) the low frequency scaling of the vibrational density of states and (III) the temperature dependence of the heat capacity. After reviewing these three problems, we will tackle them from a theoretical point of view using symmetries, effective field theory and hydrodynamics.
The lectures are mainly based on:
– “Gapped momentum states”, Physics Reports 2020 [arXiv:1904.01419]
– “Field Theory of Dissipative Systems with Gapped Momentum States”, PRD 2020 [arXiv:2004.13613]
– “Universal law for the vibrational density of states of liquids”, PNAS 2021 [arXiv:2101.01380]
– “Deformations, relaxation and broken symmetries in liquids, solids and glasses: a unified topological field theory” [arXiv:2101.05015]
– “Explaining the specific heat of liquids based on instantaneous normal modes”, PRE 2021 [arXiv:2101.07585 ]

More details @:

ИМСС УрО РАН – Цикл лекций (icmm.ru)

The link to follow them is below:

МИГ “Механизмы переноса импульса и диссипации… ” (icmm.ru)

This week, Giorgio gave his first talk in the “Holography, transport and strings” seminar series in Ljubljana about his ongoing project. You can see the slides below.

We are very happy to welcome 戴佳乐 in our TheoryLab group. 戴佳乐 will do his undergraduate thesis with us on Effective Field Theories, Hydrodynamics and Symmetries.

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Together with our colleagues from ITP Beijing and Shanghai University, we organized the annual HoloChina 2021 conference on Holography in Shanghai. It was a success !!

https://www.physics.sjtu.edu.cn/en/node/699

In a recent PRL publication (https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.015501), a research team led by professor Matteo Baggioli from SJTU Shanghai and professor Alessio Zaccone from University of Milano, discovered, for the first time, well-defined topological defects in amorphous solids by analyzing the topological structure of the dynamical displacement field under deformation. This new description based on topological higher-form symmetries quantifies the amount of non-affine displacements at the atomic/molecular level and uses it as a topological predictor of plastic events using the geometrical concept of dynamical Burgers vector. The new theory provides a very accurate prediction for the yielding point at the plasticity transition of amorphous solids, and explains the occurrence of shear bands ubiquitously observed in experiments.

Matteo just presented the recent works published in PNAS and PRL at ITP in Beijing!

http://www.itp.cas.cn/kxyj/xshd/xsbg/202106/t20210604_6079523.html

Matteo appeared in a video advertisement of the the Physics department of the university!