Sunday 5 July 2020 |

Events for day: Wednesday 04 December 2019 |

13:30 - 15:00 Weekly SeminarPhysical gauge transformations in gravity and gauge theories School ASTRONOMY In this talk, I will give a pedagogical review on the topic of large gauge transformations. To this end, I start with the simple particle mechanics and construct the solution space and its symplectic structure. Then give a definition of symmetry which is completely universal and can be extended to field theories. We will then see that in field theory this leads to the resolution that some of the gauge transformations are not redundancies and are just physical and this is related to the presence of boundaries. I will finish up by trying to review some physics behind these physical gauge transformations in high energy physics and cosmology ... 14:00 - 15:00 Weekly SeminarCondensed Matter and Statistical Physics Group Artificial Leaves for Solar Fuel Generation School PHYSICS Seminar Room (classroom A), Farmanieh Building, IPM ... 14:00 - 15:00 Weekly SeminarArtificial Leaves for Solar Fuel Generation School NANO SCIENCES Artificial Leaves for Solar Fuel GenerationAbstract:Artificial leaf is a term coined for self-sustained devices that can generate fuel from energy of the sun. A process for this purpose is splitting water into hydrogen and oxygen where hydrogen can be used directly as fuel or can be converted into higher density fuels after reaction with CO2. Low-cost generation of hydrogen is the challenge. In IPM, we have developed a low-cost device based on standard silicon solar cell technology and earthabundant electrocatalysts that can split water with >11% solar to hydrogen conversion efficiency. This efficiency is ... 14:00 - 15:00 Weekly SeminarCombinatorics and Computing Spectral gap and a conjecture by Aldous and Fill School MATHEMATICS Spectral gap and a conjecture by Aldous and Fill ... 15:00 - 16:00 Weekly SeminarBeyond The Standard Model from Holography School PARTICLES AND ACCELERATORS Abstract: We consider a SU(Nc) non-abelian gauge theory with Nf fermions in the fundamental representation and show that as Nf varies the theory can display IR conformal windows and walking couplings. We describe this exotic gauge dynamics with the holographic Dynamic AdS/QCD model. In addition Nambu Jona-Lasinio (NJL) four quark interactions can be included using Witten s multitrace prescription and their effect on the condensation will be described. Interestingly, one realizes a light Higgs-like state in ideal walking models where a combination of slowly running gauge dynamics and an NJL term trigger chiral symmetry breaking. ... |