In this talk, I will discuss the current effort of creating emulators for the non-linear power spectrum in beyond-LCDM models. I will present a pipeline that has been developed to model the matter power spectrum from large to small scales, with a focus on stage-IV photometric galaxy surveys. I will delve into the fundamental components of this pipeline, the consistency checks performed to validate it, and how effectively this new tool performs when conducting a full Bayesian parameter estimation analysis with a survey similar to LSST.
Fermi's Golden Rule (FGR) applies in the limit where an initial quantum state is weakly coupled to a continuum of other final states overlapping its energy. In this seminar I will discuss what happens away from this limit, where the set of final states is discrete, with a nonzero mean level spacing. This question arises, for example, in the context of thermalization of closed many-body quantum systems when the many body localized phase becomes unstable to avalanches. After a brief motivation, I will discuss for different symmetry classes, the universal crossovers in the average decay of the initial state as the level spacing is varied, with the Golden Rule emerging in the limit of a continuum. Among the corrections to the exponential decay of the initial state given by FGR is the appearance of the spectral form factor in the long-time regime for small but nonzero level spacing.
We have known for centuries that the brain controls vital behaviors such as the natural instinct to search for food and emotions such as fear, anxiety, and depression. However, each brain region has many different types of neurons which have different functions. Previously, it was not possible to study how a specific type of neuron affected behavior.Neuroscientists now use a method called optogenetics in which they use genetically-engineered viruses to selectively infect a single type of neuron. The virally-infected neurons then produce a protein that converts visible light into increased or decreased electrical activity in those neurons. By delivering light to the brain with lasers, we can precisely identify how changes in electrical activity of a single neuron type affects behavior. I will discuss how we used optogenetics to discover neurons that control numerous survival behaviors, such as escaping from threats and seeking food. I will also show how these findings used contributions from diverse fields, such as microbiology, biophysics, optics and genetics, highlighting how multidisciplinary insights are a key feature of modern neuroscience.
