Two Talks: Relativistic Effect In Galaxy Clustering As A Novel Probe Of Inflationary Cosmology (speaker: Jaiyul Yoo, University Of Zurich); Talk 2: Using Galaxies As Natural Telescopes: Disentangling The Quasars (speaker: Ana Mosquera, US Naval Academy)

Monday April 4, 2016 12:05 pm
Marlar Lounge (37-252)

Talk #1

Relativistic Effect in Galaxy Clustering as a Novel Probe of Inflationary Cosmology
speaker:   Jaiyul Yoo, University of Zurich

Precision measurements in current and future galaxy surveys bring in new challenges, demanding substantial advances in theoretical modeling. I will discuss the recent theoretical advances in formulating galaxy clustering in a general relativistic context. The relativistic effect in galaxy clustering or the deviation from the standard Newtonian description becomes substantial on large scales, in which modified gravity theories deviate from general relativity and the fingerprint of the inflationary epoch remains in its pristine form.
I will discuss how the subtle relativistic effect in cosmology can be used to test general relativity and probe signatures of the early Universe.

Host:  Mark Vogelsberger

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Talk #2

Using galaxies as natural telescopes: Disentangling the quasars’ X-ray emission regions with microlensing.
speaker: Ana Mosquera, US Naval Academy

As accreting supermassive black holes, AGNs are among the most physically interesting objects in the Universe. They also help to regulate star formation and the evolution of galaxies. One of their defining characteristics is their X-ray emission, but the origin and spatial extent of this emission is still unknown in large part because we have lacked the means to resolve the central engine.  However, microlensing in multiply imaged gravitationally lensed quasars allows us to zoom in on in the structure of AGN and explore their physics in more detail. Quantitative microlensing X-ray size constraints exist for 6 systems, setting the first upper limits for these emitting regions. Obtaining these pioneering results was possible due to the high resolution and sensitivity of the CXO. The next frontier is to explore possible correlations of the X-rays sizes with black hole mass and spectral index, as well as to set constraints on the scaling of the size with X-ray energy. In my talk I will briefly describe our methodology and results, and discuss key aspects of future surveys that would help us to obtain unprecedented results in the field.

Host:  Monica Turner