| Friday 26 April 2024 | |
| Events for day: Wednesday 09 May 2018 |
Recent Trends in String Theory and Related Topics PHYSICS Farmanieh Conference Hall ... 13:30 - 15:00 Weekly Seminar Adiabatic Modes in Cosmology School ASTRONOMY In Cosmological perturbation theory, there are solutions to the Einstein equations that locally resemble pure coordinate transformations––they can be locally gauged away. Until today, cosmological observations have revealed that these so called ``Adiabatic Modes" comprise all of the fluctuations that we see in the universe. On the other hand, in every single field models for inflation, the only scalar mode that gets excited and seeds all of the density perturbations in CMB and LSS, is one and only one adiabatic mode. The adiabaticity of this mode implies that single field models for inflation enjoy infinity many asymptotic symmetries. These s ... 14:00 - 15:00 Weekly Seminar Optical Studies of Dirac Materials School NANO SCIENCES Optical Studies of Dirac Materials The fast-evolving field of condensed matter physics is witnessing a rapid development of a new class of materials, called Dirac materials. The low-energy electronic excitation in these semimetals behaves like massless Dirac particles (linear energy dispersion). In this talk, I will discuss experimental optical studies of two prominent Dirac materials that have unique physical properties: graphene (two-dimensional) and tantalum arsenide (three-dimensional). While the former can be regarded as the father of materials with a symmetry-protected Dirac spectrum, the latter is an examp ... 15:00 - 16:00 Weekly Seminar LYSO-based Precision Timing Detectors School PARTICLES AND ACCELERATORS Particle detectors based on scintillation light are particularly well suited for precision timing applications with resolutions of a few 10s of ps. The large primary signal and the initial rise time of the scintillation light result in very favorable signal-to-noise conditions with fast signals. In this talk, I will describe timing studies using a LYSO-based sampling calorimeter with different wavelength-shifting light extraction and photosensors. I will explain the contributions of various steps of the signal generation to the total time resolution, and demonstrate its feasibility as a radiation-hard technology for calorimeters at high inten ... 16:00 - 18:00 Neuroimaging Journal Club Resting-state connectivity biomarkers define neurophysiological subtypes of depression School COGNITIVE SCIENCES Venue: School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Opposite the ARAJ, Artesh Highway, Tehran, Iran ... |