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High Energy Physics Seminar

Monday, January 6, 2020
4:00pm to 5:00pm
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Lauritsen 469
Separate Universe Techniques for Nonlinear Gravitational Evolution
Marilena Loverde, C.N. Yang Institute for Theoretical Physics, SUNY Stony Brook,

I will introduce the "separate universe" approach to determining some aspects of nonlinear gravitational evolution: specifically the bias of tracers such as halos and voids and squeezed limit bispectra. I will motivate and define the separate universe, and then show how it can be generalized for cosmologies with multiple fluctuating components in the energy density -- either different fluids or adiabatic and isocurvature modes. Finally, I'll describe results using these techniques that explicitly demonstrate how small-scale observables depend on the growth-history of long-wavelength density fluctuations and new small-scale observables that can arise.

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