Abstract:
The primordial density perturbations seen in the cosmic microwave background have collapsed under gravity to form the large-scale structure we see in the universe today. This evolution is non-linear, and therefore introduces coupling between Fourier modes that would otherwise be independent. I will present two consequences of this non-linear coupling. Halo sample variance (arXiv:1406.3330): Gaussian estimates for the errors in large-scale structure measurements exaggerate the scientific impact of these measurements. Non-linear evolution and finite volume effects are both significant sources of non-Gaussian covariance, which reduce the ability of power spectrum measurements to constrain cosmological parameters. I will present a joint likelihood for cluster counts, power spectrum and bispectrum, including the non-Gaussian covariances, and show that a joint analysis of these observables can reduce this information loss. In some cases, the resulting improvement on cosmological parameters is equivalent to doubling the survey area. Lyman-alpha - CMB lensing bispectrum (arXiv:1607.03625): The Lyman-alpha forest seen in the spectra of quasars is a powerful tool for constraining warm dark matter models and the neutrino masses, as well as properties of the intergalactic medium. Its use as a cosmological probe relies on modeling the connection between neutral gas and dark matter. I will present the first detection of the correlation between the Lyman-alpha forest and the cosmic microwave background, using data from BOSS and Planck. This signal quantifies the non-linear response of the neutral hydrogen to a large-scale overdensity, and thus tests our understanding of the connection between neutral gas and the dark matter.
The generation of a stochastic gravitational wave background is a key prediction of cosmological theories of inflation. At large angular scales, these gravitational waves imprint a "B-mode" polarization pattern in the Cosmic Microwave Background, providing a new window into the physics of the early universe and helping to constrain and distinguish between inflationary models. SPIDER is a balloon-borne telescope that has been uniquely optimized to search for the inflationary B-mode signature in the CMB. Over the course of two Antarctic flights, SPIDER will make polarization maps over 10% of the sky in three frequency bands with degree-scale angular resolution. After an overview of the instrument and science goals, preliminary results from SPIDERs 2015 flight will be presented along with a summary of progress towards the second flight.
Abstract:
"After the discovery of Higgs boson by the ATLAS and CMS experiments at the LHC in 2012, a new era of studying the properties of this new particle has begun. In this talk, I will give a brief overview of Higgs boson property measurements using LHC Run 1 data, and then focus on the measurements of Higgs boson production in the four-lepton decay channel and in combination with the diphoton decay channel using 13.3 fb-1 to 14.8 fb-1 of Run 2 data collected at ?s=13 TeV by the ATLAS detector."