24 NOV 2021
13:30 - 15:00

During this talk, I will review our recent works on stochastic formalism in the presence of electromagnetic fields in the early universe. I extend the stochastic formalism to the setup of the models containing a U(1) gauge field in order to revise Primordial magnetogenesis during inflation. I show that the stochastic noises of electromagnetic perturbations have significant effects on the dynamics of the system. These effects can not be neglected even in the leading order in contrast with the stochastic noises of the scalar fields.

24 NOV 2021
14:00 - 15:00

Abstract:
An increasing number of 2D materials are being deployed for different applications across energy generation, conversion and storage sectors. Among these materials, however, graphene oxide and not graphite oxide, as the most technologically relevant 2D material of choice for energy-related applications, has gained a stronghold and is near the final stage of commercialization ready to enter the mass market. This calls for a thorough understanding of the behaviour of this intriguing atomically thin material and possibly other members of the mushrooming family of 2D materials in aquatic environment as their toxicity can easily pose a threat to aquatic life at global levels not seen before due to the huge surface area of 2D materials (~2000 m2/g). Although a great deal of research has been dedicated to this subject, a key misconception is the treatment of these materials as a sphere with an effective radius or that their flat surface would fold upon itself resulting in a much lower aspect ratio and consequently lower available surface area. This essentially implies a much higher critical concentration at which it is alleged that these 2D materials are toxic to the aqueous environment. Our findings presented here point out that this is not a valid assumption by showing that 2D materials in saline waters hold their flat morphology and therefore pose a greater challenge for the environment rather than their professed 3D conformed counterparts.


Date: Wednesday, November 24, 2021

Time: 14:00-15:00

To join the webinar, please follow this link:
https://www.skyroom.online/ch/schoolofphysics/condensed-matter-and-statistical-physics
and log in as guest.

Organized by: Condensed Matter and Statistical Physics Group, School of Physics (IPM)

Queries about this event should be addressed to Dr. A. Faridi at azadeh.faridi@ipm.ir

24 NOV 2021
16:30 - 18:30

How can we understand all saturated homogeneous ideals in a poly- nomial ring? Hilbert schemes give a geometric answer to this question. After surveying some key features of these natural parameter spaces, we present a complete classification of the smooth Hilbert schemes. Time permitting, we will also reinterpret the smooth Hilbert schemes as suitable generalizations of partial ag varieties. This talk is based on joint work with Roy Skjelnes (KTH).

https://zoom.us/join
Meeting ID: 875 4619 4914
Passcode: 474975

24 NOV 2021
15:30 - 17:30

This talk has two parts. In the first part, we will explore some basic aspects of the semantics in Boolean-valued models using tools developed in conditional set theory. The focus will be on Boolean-valued models built from measure algebras. We will describe some basic definitions and theorems in the naive set theory, topology, measure theory, and functional analysis in such models and show with a few examples how such Boolean-valued theorems can be proved from first things and by hand using Boolean reasoning and the exhaustion principle (and without employing a transfer principle). In the second part of the talk, we will interpret some of the internal results of a Boolean-valued model relative to a measure algebra as structures in a standard model, and conversely give some ways how to identify with certain standard objects corresponding objects in a Boolean-valued model. Finally, we will use these connections to give several new applications of Boolean-valued models to the standard model which include examples from ergodic theory, measure theory, and stochastic optimal control. I will also present some open-end questions. The talk will be as much as possible self-contained. This talk is to a large extent based on several published and unpublished joint works with several coauthors.

https://us06web.zoom.us/j/87929792112?pwd=WWNnTkEwOFQwRDdOVXNaK1UzZHBFZz09
Meeting ID: 879 2979 2112
Passcode: 496589

23 NOV 2021
14:00 - 15:00

Abstract:
I will review some universal features of quantum gravity and use them to narrow the space of field theories with minimal supersymmetry in d > 6. We will see that the restrictions in 9d do not allow theories that have not been already realized in string theory. This observation demonstrates the validity of the String Lamppost Principle that all consistent theories of quantum gravity are in the String Landscape.

Date: Tuesday, November 23th
2:00 p.m (Tehran time)


Zoom. (click)
Meeting ID: 870 1139 0957
Passcode: 926498

23 NOV 2021
15:00 - 17:00

I will begin with a brief overview of some well-known results in incidence geometry and go on to discuss a recent joint work with Thang Pham and Audie Warren, in which we prove upper bounds on the number of incidences between sets of points and conics over finite fields. I will conclude the talk by considering applications to certain finite field variants of ErdH{o}s type problems on the number of distinct algebraic distances formed by point sets, including improvements to results of Koh and Sun (2014) and Shparlinski (2006).




Zoom link:

https://us06web.zoom.us/j/9086116889?pwd=WGRFOGZWZ1FOMXJrcWpJMWFqUFIvQT09


Meeting ID: 908 611 6889


Passcode: 362880

Video:

You can see the video of this talk by clicking
here.

23 NOV 2021
18:00 - 19:00

Abstract: Recent advances in AdS/CFT suggest that the near-horizon dynamics of black holes can be described by unitary random matrix systems. Motivated by these developments, I will discuss how the energy spectrum of a system with a generic random Hamiltonian matrix affects its early and late time thermalization behaviour using the spectral form factor (which captures the time-dependence of two-point correlation functions) and connect it to the discussion of gravitational wave echoes. In particular, I will demonstrate that it is possible for quantum chaotic systems to exhibit echoes if the energy spectrum contains many clusters of eigenvalues which are regularly spaced from each other. I will discuss the example of a randomly coupled oscillator system and show that at weak coupling the form factor exhibits echoes. I will speculate on the holographic interpretation of a system of weakly coupled oscillators, and give a heuristic picture of how they might describe the thermalization behaviour of a black hole geometry with a membrane that cuts off the geometry at the stretched horizon. I will also discuss the role that symmetries play in quantum chaotic systems that exhibit echoes.
Paper: https://arxiv.org/abs/2110.03188
( for participating in this event, please contact us: "particles@ipm.ir" )

22 NOV 2021
16:00 - 18:00

Hegel's conception of "multiple modernities"

https://www.skyroom.online/ch/ipmseminars/ipm-seminars-fall2021

User: biweeklyseminars
Pass: biweeklyseminars