Events

<<	March 2017	>>

Add an Event

Edit This Event

<< Fall 2016	Spring 2017	Summer 2017 >>
Subscribe your calendar or receive email announcements of events

Theory Seminar (High Energy/Cosmology)

Cosmology from Non-Linear Weak Lensing

Date: Tuesday, March 28th

Time: 3:30 pm

Place: 5280 Chamberlin Hall

Speaker: Zoltan Haiman, Columbia Univ

Abstract: Several large astronomical surveys have either been proposed or are underway to measure weak lensing distortions of up to a billion galaxies. This will allow accurate measurement of the lensing shear field in the small-scale, non-linear regime, where non-Gaussian features can contain significant cosmological information. I will report on results from a large suite of ray-tracing N-body simulations in different cosmologies, and discuss constraints from the number counts of lensing peaks (i.e. from the number of maxima as a function of their height), and from other statistics probing the non-linear<br>
regime. These statistics can tighten cosmological constraints by a factor of two, compared to using two-point statistics alone. A recent application of this approach to the CFHTLenS survey has confirmed this for the parameters (Omega_m,sigma_8). I will comment on the theoretical and simulation challenges for larger lensing surveys in<br>
the future.

Host: Joshua Berger

Presentation: Haiman-slides.pdf

Add this event to your calendar