| Friday 19 April 2024 | |
| Events for day: Wednesday 08 July 2020 |
| 11:00 - 12:00 Online Computational Nanoscience journal club Broken adiabaticity induced by Lifshitz transition in MoS2 and WS2 single layers School NANO SCIENCES Broken adiabaticity induced by Lifshitz transition in MoS2 and WS2 single layers Abstract: The breakdown of the adiabatic Born-Oppenheimer approximation is striking dynamical phenomenon, however, it occurs only in a handful of layered materials. Here, I show that adiabaticity breaks down in doped single-layer transition metal dichalcogenides in a quite intriguing manner. Namely, significant nonadiabatic coupling, which acts on frequencies of the Raman-active modes, is prompted by a Lifshitz transition due to depopulation and population of multiple valence and conduction valleys, respectively. The outset of ... 11:00 - 12:00 Wednesday Weekly Seminar-skyroom Time Evolution of Entanglement entropy for Thermofield Double States School PARTICLES AND ACCELERATORS Abstract: We review the time evolution of the entanglement entropy of the thermofield double (TFD) states for scalar quantum field theory on a circle?. ?It is observed that the entanglement entropy growth linearly in early times and saturates after a time of the order of the length of subregion?, ?similar to the time evolution of the entanglement entropy in non-equilibrium quantum systems following quench?. The ?zero ?mode? effect has also been shown to manifest itself as logarithmic growth???, ?which is derived analytically for a subsystem consisting of a single degrees of freedom on each side of the TFD at the massless limit?. 13:30 - 15:00 Weekly Seminar (Online) The consistent D -> 4 Einstein-Gauss-Bonnet gravity https://www.skyroom.online/ch/soa/weekly-seminar School ASTRONOMY The so-called Lovelock theorem implies that the Einstein-Hilbert action is unique in four dimensions D=4. Recently, it was claimed that nontrivial dynamics from the Gauss-Bonnet term, which is not dynamical in D=4, can be achieved through a dimensional regularization process if we start from D(>4) dimensions and then take the D -> 4 limit. Taking this nontrivial contribution into account, they found a new theory of D->4 Einstein-Gauss-Bonnet gravity and bypassed the Lovelock theorem. Soon after that, some doubts were raised about the idea. In this talk, in the first part we clarify the source of doubts. In the second part, we provide consiste ... 14:00 - 15:00 Weekly Seminar Condensed Matter and Statistical Physics Group The effect of noise on Casimir nano-machines School PHYSICS It is already shown that two sinusoidally corrugated plates exert lateral Casimir force to each other. Utilizing lateral Casimir force, it is possible to design several nanomachines. We investigate the effect of noise on Casimir nanomachines. We use a corrugated plate (rack) and a corrugated cylinder (pinion) to design a nano-sensor. We show that the designed Casimir nanomachine is an excitable system. Observing the temporal position signal of the pinion, Casimir force along with friction coefficient could be extracted. Utilizing this method, Casimir force amplitudes of the order 0.1-1 pN could be measured. It is also shown th ... 14:00 - 15:00 Weekly Webinar The effect of noise on Casimir nano-machines. School NANO SCIENCES The effect of noise on Casimir nano-machines Abstract: It is already shown that two sinusoidally corrugated plates exert lateral Casimir force to each other. Utilizing lateral Casimir force, it is possible to design several nanomachines. We investigate the effect of noise on Casimir nanomachines. We use a corrugated plate (rack) and a corrugated cylinder (pinion) to design a nano-sensor. We show that the designed Casimir nanomachine is an excitable system. Observing the temporal position signal of the pinion, Casimir force along with friction coefficient could be extracted. Utilizing this method, Casimir fo ... 15:30 - 17:00 Geometry and Topology Seminar Lorentzian geometry and cohomogeneity one actions School MATHEMATICS In this talk, we introduce, briefly, the basis of Lorentzian geometry and cohomogeneity one actions. We also, introduce the Einstein universe and consider an interesting cohomogeneity one action on $mathbb{Ein}^{1,2}$. A smooth manifold $M$ equipped with a metric tensor $ extbf{g}$ of signature $(1, n)$ is called a Lorentzian manifold. Precisely, the restriction of $ extbf{g}$ to the tangent space $T_pM$ is of the form $−x_1^2+x_2^2+cdots+x_n^2$. Let $G$ be a Lie group which acts on a smooth manifold. Then the orbit of $G$ at point $pin M$ is $G(p) := {gp : g in G}$. If $G$ acts on $M$ smoothly, then every orbit of $G$ is ... 15:30 - 17:30 Mathtematical Logic Weekly Seminar Interpolative Fusions School MATHEMATICS The new notion of interpolative fusions provides a unified framework for studying many examples of "generic constructions" in model theory. Some, like structures with generic predicates, or algebraically closed fields with several independent valuations, are explicitly interpolative fusions, while others, like structures with generic automorphisms, or fields with generic operators, are bi-interpretable with interpolative fusions. The idea is to take two expansions T and T' of a common reduct theory and study models of their union such that the T and T' structures interact "randomly" up to constrains imposed by the common reduct. If T and T' a ... 16:00 - 17:30 Theoretical Neuroscience Journal Club Online The Effect of Spatially Inhomogeneous Extracellular Electric Fields on Neurons School COGNITIVE SCIENCES Organized by: School of Cognitive Sciences to receive the link to join online, please send email to theoretical.neurosci.ipm@gmail.com Abstract: >> schedule >> Poster of this session |