Events Archive

Special Joint Gravity Group and Gravity Initiative Seminar: Neil Cornish|Montana State| "Gravitational Wave Astronomy: Where we are at, and What’s next”
Fri, May 20, 2022, 12:00 pm12:00 pm

Following the first detection of a binary black hole merger in 2015, the number of gravitational wave events has grown to almost one hundred, including binary neutron star mergers and mixed black hole, neutron star mergers. Going forward, the next few years should bring a wealth of new discoveries, including several more neutron star mergers…

Gravity Group Lunch Seminar | Yilun Guan (Pittsburgh) & Brandon Hensley (Princeton) "The ACT View of the Galactic Center"
Fri, May 7, 2021, 12:00 pm12:00 pm

We present new maps of the Galactic Center in total intensity and polarization made with the Atacama Cosmology Telescope (ACT). We combine dedicated, arcminute-resolution ACT observations over a 32 deg^2 field with Planck intensity and polarization data at similar frequencies to produce maps with fidelity on both small and large angular scales…

Gravity Group Seminar | Zach Atkins, "Map-based Noise Simulations for ACT Data" Suren Gourapura, "r Error Budget for SPIDER's First Flight"
Fri, Apr 30, 2021, 12:00 pm12:00 pm
Zachary Atkins, Princeton University "Map-based Noise Simulations for ACT Data"

The next analysis of ACT data will use precision-cosmology-capable maps of the microwave sky based on data taken by the Advanced ACT detector arrays since 2017. The maps will cover the full Advanced ACT footprint (~44% f_sky, see Aiola et al. 2020 and Mallaby…

Gravity Group Lunch Seminar | Sarah Marie Bruno, "The projected impact of commercial satellite constellations on ground-based astronomy" & Roman Kolevatov, "The DMRadio Experiment at Princeton"
Fri, Apr 23, 2021, 12:00 pm12:00 pm

Sarah Marie Bruno, Princeton University 
"The projected impact of commercial satellite constellations on ground-based astronomy"

The ongoing commercialization of satellite technology is leading to the ubiquity of privately owned and operated satellite spacecraft in low-Earth orbits. These satellites can be used for…

Gravity Group Seminar | Xue (Sherry) Song, Joseph van der List, and Corwin Shiu, PU "B-mode Constraint from SPIDER's First Flight"
Fri, Apr 9, 2021, 12:00 pm12:00 pm

SPIDER is a balloon-borne telescope designed to map the B-mode polarization of the cosmic microwave background (CMB) on degree angular scales. SPIDER’s 2015 flight mapped 4.8% of the sky at 95 and 150 GHz. In this talk, we report the results of internal consistency tests performed on the data to control against instrumental systematics, and…

Gravity Group Lunch Seminar | Oliver Philcox, PU "Have we exhausted the galaxy two-point function?"
Fri, Apr 2, 2021, 12:00 pm12:00 pm

Throughout the past three decades, the analysis of spectroscopic surveys has focussed around the two-point function of the galaxy overdensity field, masquerading either as the correlation function or the Fourier-space power spectrum. Today, theoretical interest has shifted towards other statistics, in particular the higher-point functions. Does…

Gravity Group Lunch Seminar, Saptarshi Chaudhuri | Princeton "Axions and DM Radio at Princeton"
Fri, Dec 18, 2020, 12:00 pm12:00 pm

I introduce DM Radio, a lumped-LC oscillator search for axion dark matter. I review the detection scheme and design, current experimental status, and future prospects, including the use of electromagnetic quantum metrology in previously-unexplored kHz and MHz frequency ranges. Experimental efforts at Princeton, in particular probes of loss…

Gravity Group Lunch Seminar, Anne Gambrel | KICP, U. Chicago "The XFaster Power Spectrum and Likelihood Estimator and its Application to SPIDER"
Fri, Nov 20, 2020, 12:00 pm12:00 pm

Every analysis of cosmic microwave background observations faces the challenge of compressing large amounts of data into the comparatively tiny spaces of power spectra and cosmological parameters. A variety of pipelines have been used to accomplish this task, balancing the goals of optimally computing these quantities and their errors while…

Gravity Group Seminar | Speakers TBA "The Simons Observatory Instrument: Status of Ongoing Research at Princeton"
Fri, Nov 13, 2020, 12:00 pm12:00 pm

The Simons Observatory (SO) will be a cosmic microwave background (CMB) survey experiment with four small-aperture telescopes (SATs) and one large-aperture telescope, which will observe from the Atacama Desert in Chile. In total, SO will field over 60,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280…

Gravity Group Seminar | Status of the Atacama Cosmology Telescope
Fri, Oct 23, 2020, 12:00 pm12:00 pm

Adri Duivenvoorden, Zack Li, Brandon Hensley, Jo Dunkley, and Lyman Page will update us on the status of the Atacama Cosmology Telescope (ACT).

Gravity Group Lunch Seminar, Justin Ripley | DAMTP "Classical modifications to Einstein's General Relativity around black holes"
Fri, Oct 16, 2020, 12:00 pm12:00 pm

In this talk I will discuss recent work on the dynamics of black holes in Einstein dilaton Gauss-Bonnet (EDGB) gravity. This modified gravity theory can be motivated by effective field theory reasoning, and admits scalarized black hole solutions. These two facts make it an interesting candidate theory to constrain using binary black hole,…

Gravity Group Seminar | Meet the Gravity Group
Fri, Sep 18, 2020, 12:00 pm12:00 pm

We will kick off this season with a "Meet the Gravity Group" event. The format will be the same as last year's: all of us, be we juniors getting started on our Fall papers or emeritus, will get one slide and one minute to introduce ourselves to our new colleagues and share our spring / summer updates with the group.


Gravity Group Lunch Seminar, Daniel Dutcher | U. Chicago “Measuring the Polarization of the CMB with SPT-3G” (CANCELED)
Fri, Mar 13, 2020, 12:00 pm12:00 pm

Observations of the cosmic microwave background form the pillar of our current understanding of cosmology. Measurements of the temperature and polarization anisotropies of the CMB extending to small angular scales set tight constraints on cosmological parameters, probing both the standard LCDM model and the physics of inflation. Making these…

Gravity Group Lunch Seminar, Justin Ripley & Joseph van der List | Princeton
Fri, Mar 6, 2020, 12:00 pm12:00 pm

Justin Ripley, Princeton University "Modeling the 'ringdown' of a Kerr black hole"

We present on progress to compute the second order metric perturbation of a Kerr black hole. We will first introduce the Teukolsky equation, and explain how it is used to understand first order perturbations of a Kerr black hole. We…

Gravity Group Lunch Seminar, Zack Li & Rita Sonka | Princeton
Fri, Feb 28, 2020, 12:00 pm12:00 pm

Zack Li, Princeton University
"ABS, ACT, and Planck via the Simons Observatory Power Spectrum Pipeline"

I will present an open-source and validated pipeline for curved sky CMB power spectrum analysis, intended for use with Simons Observatory. I'll discuss cross-correlations of maps from the ground-based ACT and…

Gravity Group Lunch Seminar, Ivan Padilla | JHU "Cosmology Large Angular Scale Surveyor: Circular polarization at 40 GHz"
Fri, Feb 7, 2020, 12:00 pm12:00 pm

Large angular scale polarimetry of the CMB will provide powerful constraints on the cosmological parameters r, the tensor-to-scalar ratio, and tau, the optical depth to the epoch of reionization. The Cosmology Large Angular Scale Surveyor (CLASS) is targeting these scales by conducting a survey from the Atacama, covering ~75% of the sky, across…

Gravity Initiative Lunch, Antonios Tsokaros | University of Illinois "Numerical methods in general relativity and the physics of compact objects"
Mon, Dec 9, 2019, 12:30 pm12:30 pm

Every astrophysically realistic simulation needs accurate initial data and in this talk I will present methods to obtain such solutions for a variety of problems. In particular I will focus on a new initial data formulation to solve the full set of Einstein equations for spacetimes that contain a black hole under general conditions. As an…

Gravity Group Lunch Seminar, Oliver Philcox | Princeton University "Detection and Removal of Dust Foregrounds in the B-mode CMB via Statistical Anisotropy"
Fri, Dec 6, 2019, 12:00 pm12:00 pm

Searches for inflationary gravitational wave signals in the CMB B-mode polarization are expected to reach unprecedented power over the next decade. A major difficulty in these ongoing searches is that Galactic foregrounds such as dust can easily mimic inflationary signals. Though typically foregrounds are separated from primordial signals using…

Gravity Group Lunch Seminar, Andrew Chael | PCTS "The black hole-jet connection in M87: linking simulations to VLBI images"
Fri, Nov 22, 2019, 12:00 pm12:00 pm

The Event Horizon Telescope (EHT) has produced the first image of the 1.3 mm-wavelength emission around the black hole "shadow" at the heart of M87. The hot plasma in the accretion flow around M87's central black hole illuminates the spacetime, and the flow's magnetic field extracts energy from the black hole to launch the famous relativistic…

Gravity Group Lunch Seminar, Corwin Shiu | Princeton "A design of a wideband 30/40 GHz diplexed camera suitable for BICEP Array"
Fri, Oct 25, 2019, 12:00 pm12:00 pm

Abstract: Accurate understanding of astrophysical foregrounds is crucial in recovering the underlying CMB signal. In this talk I will discuss the design and performance of a camera that will be powerful at characterizing synchrotron emissions. The camera is comprised of slotted bowtie antenna elements coherently summed in a…