Friday 27 September 2024 |
Events for day: Wednesday 16 September 2020 |
11:00 - 12:00 Online Computational Nanoscience journal club Resonant Photovoltaic Effect in Doped Magnetic Semiconductors School NANO SCIENCES Resonant Photovoltaic Effect in Doped Magnetic Semiconductors Abstract: The rectified nonlinear response of a clean, time-reversal symmetric, undoped semiconductor to an ac electric field includes a well known intrinsic shift current. We show that when Kramers degeneracy is broken, a distinct second order rectified response appears due to Bloch state anomalous velocities in a system with an oscillating Fermi surface. This effect, which we refer to as the resonant photovoltaic effect, produces a resonant galvanic current peak at the interband absorption threshold in doped semiconductors or semimetals with ap ... 11:00 - 12:00 Wednesday Weekly Seminar-skyroom Constraining the top quark effective field theory using the top quark pair production in association with a jet at future lepton colliders School PARTICLES AND ACCELERATORS Abstract: Our main aim in this paper is to constrain the effective field theory describing the top quark couplings through the e?e+?tt~+jet process. The analysis is carried out considering two different center-of-mass energies of 500 and 3000 GeV including a realistic simulation of the detector response and the main sources of background processes. The expected limits at 95% CL are derived on the new physics couplings such as tt~gamma, tt~Z, and tt~g for each benchmark scenario using the dileptonic tt~ final state. We show that the 95% CL limits on dimensionless Wilson coefficients considered in this analysis could be probed down to 10?4. 14:00 - 15:00 Weekly Seminar Condensed Matter and Statistical Physics Group Reverse Dance in an External Flow: Meet Onsager again! School PHYSICS Abstract: A driven fan that spins to create a flow of air would conversely rotate, if we turn it off, and subject it to a strong external flow. This is a classic example of reciprocity between cause and effect, in a life scale experiment. In small scale hydrodynamics, however, when the Reynolds number is quite low, a swimmer (pump) would generate a net motion (flow) only if its constructing parts non-trivially follow a pattern of motion which breaks time reciprocity. Here, considering a simple and well-controlled system of two micron-sized beads, we investigate if the mentioned exchange of physical cause and effect also holds ... 15:30 - 17:30 Mathtematical Logic Weekly Seminar Tameness for Set Theory School MATHEMATICS We show that (assuming large cardinals) set theory is a tractable (and we dare to say tame) first order theory when formalized in a first order signature with natural predicate symbols for the basic definable concepts of second and third order arithmetic, and appealing to the model-theoretic notions of model completeness and model companionship. Specifically we develop a general framework linking generic absoluteness results to model companionship and show that (with the required care in details) a $Pi_2$-property formalized in an appropriate language for second or third order number theory is forcible from some T extending ZFC + large car ... 16:00 - 19:00 Thesis Defense Neural representation of familiar faces in human visual cortex School COGNITIVE SCIENCES . ... |