Astrophysics Seminars

Nov
21
2019

Institute for Advanced Study Informal Astrophysics Seminar

Non-Gaussianity & the Spectral Tilt
11:00am|Bloomberg Hall, Astrophysics Library
Cosmological observations have revealed a small but non-zero deviation for scale invariance but remain consistent with perfectly Gaussian initial conditions. I will discuss how non-Gaussianity is related to deviations from exact scale and conformal...
Nov
14
2019

Institute for Advanced Study Informal Astrophysics Seminar

Star Cluster Populations: The Link Between Star Formation and Galaxy Formation
Michael Fall
11:00am|Bloomberg Hall, Astrophysics Library
This talk presents a general picture of star cluster populations, from their formation in the clumpy ISM to their eventual dissolution in the smooth stellar field. The picture is general or unified in the sense that it encompasses most traditional...
Nov
07
2019

Institute for Advanced Study Informal Astrophysics Seminar

Addressing the Initial Patch Problem of Inflation
11:00am|Bloomberg Hall, Astrophysics Library
After reviewing the initial patch problem for inflation, I present numerical and analytical results that allow us to investigate arbitrarily inhomogenous spacetimes, and that show that this problem is non-existent: non-trivial mathematical reasons...
Oct
31
2019

Institute for Advanced Study Informal Astrophysics Seminar

Solar Interiors, Helioseismology and Neutrinos
11:00am|Bloomberg Hall, Astrophysics Library
For more than 20 years helioseismology, the study of solar oscillations, has provided an exquisite picture of the solar interior structure. However these oscillations, which are standing acoustic waves in the solar interior, have diminishing...
Oct
24
2019

Institute for Advanced Study Informal Astrophysics Seminar

Characterizing Star-Planet Systems with Precision Spectroscopy
Megan Bedell
11:00am|Bloomberg Hall, Astrophysics Library
More than two decades after the discovery of the first exoplanet with radial velocity (RV) measurements, vast quantities of data exist from dedicated planet-hunting spectrographs. These spectra play an important role not only in the discovery and...
Oct
17
2019

Institute for Advanced Study Informal Astrophysics Seminar

Mid-band Atomic Gravitational wave Interferometric Sensor (MAGIS)
11:00am|Bloomberg Hall, Astrophysics Library
Gravitational waves provide a new window to the universe. Opening new bands in the gravitational spectrum is expected to yield a wealth of information. I will discuss a new experiment: the Mid-band Atomic Gravitational wave Interferometric Sensor...
Oct
10
2019

Institute for Advanced Study Informal Astrophysics Seminar

Universal Interferometric Signatures of a Black Hole's Photon Ring
Alexandru Lupsasca
11:00am|Bloomberg Hall, Astrophysics Library
The Event Horizon Telescope image of the supermassive black hole in the galaxy M87 is dominated by a bright, unresolved ring. General relativity predicts that embedded within this image lies a thin ``photon ring," which is composed of an infinite...
Oct
03
2019

Institute for Advanced Study Informal Astrophysics Seminar

Long-Period Eclipsing Systems from Kepler Data
11:00am|Bloomberg Hall, Astrophysics Library
The prime Kepler mission provided high-precision photometric light curves for 10^5 stars continuously over 4 years. While the search for exoplanetary transits in these data was originally focused on signals with periods less than about a year...
Sep
26
2019

Institute for Advanced Study Informal Astrophysics Seminar

Optimization Ideas, Algorithms, Tools, and Some Astro-Related Examples
Robert Vanderbei
11:00am|Bloomberg Hall, Astrophysics Library
In science and engineering many problems can be described as optimization problems. Many of these problems are somewhat vaguely defined and are best solved by clever heuristics. But also, many are very precisely defined and are best solved by...
Sep
19
2019

Institute for Advanced Study Informal Astrophysics Seminar

Circumplanetary Disk Dynamics in the Isothermal and Adiabatic Limits
11:00am|Bloomberg Hall Astrophysics Library
The dynamics of circumplanetary disks (CPDs), mini disks formed around protoplanets embedded in their natal protoplanetary disks, is expected to regulate how the planets accrete solids and gas, as well as how satellite systems are formed. Previous...