Cosmology Seminar

Cosmology Seminars are held at on Mondays at 11 am during the academic year, on the 3rd floor Varian conference room. These are more focused and less didactic than the colloquium, and provide a stage for younger researchers to present their work in more detail.  

We have put cosmology seminars on hold for the rest of Spring 2020 while we are sheltering in place.  Astrophysics Colloquia and KIPAC tea are proceeding by zoom.

Please contact Alex Amon, Kirk Barrow, Jessie Muir or Risa Wechsler for more information.

3D mapping of the dusty, magnetized ISM with starlight polarization

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Speaker
Gina Panopoulou (Caltech) via zoom

The coming decade will mark a milestone in our understanding of interstellar magnetism: achieving a first reconstruction of the Galactic magnetic field in 3D. This will be crucial for progress in fields such as CMB cosmology and cosmic ray physics. Achieving this goal relies on the combination of (a) high-accuracy data that probe interstellar magnetism and (b) novel algorithms that enable the combination of different datasets. A first step towards this direction can be made through the use of starlight polarization in combination with stellar distances.

Gravitational wave astrophysics and cosmology with large galaxy surveys

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Location

Campus, Varian 355

Speaker
Antonella Palmese (Fermilab)

In the occasion of the exciting discovery of the electromagnetic counterpart of the GW170817 gravitational wave event, the Dark Energy Survey (DES) collaboration produced a series of studies covering different aspects of the event. In particular, these studies showed that observations of the GW170817 host galaxy can provide information about the formation of the binary neutron star that merged, producing the gravit

Uncovering the nature of dark matter with stellar streams in the Milky Way

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Location

Campus, Varian 355

Speaker
Ana Bonaca (Harvard Smithsonian Center for Astrophysics)

Stars orbiting in the halo of our galaxy, the Milky Way, are a window into the distribution of dark matter. Tidally disrupting star clusters are especially valuable tracers, because in pristine conditions they produce thin stellar streams of nearly uniform density.

Bright (active) Galaxies in Dark Matter halos

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Location

Campus, Varian 355

Speaker
Shadab Alam (University of Edinburgh)

The bright galaxies comes in different colours and show different activities. Some are red, some blue and others have angry supermassive blackholes. These galaxies acts as the doorway to the cosmological universe we live in. Our understanding of inner working of universe and its mysterious dark components of matter and energy depends on the very large scale structure formed by these bright galaxies.

Stellar Property Statistics of Massive Halos: Common Kernel Shapes from Multiple Cosmological Hydrodynamics Simulations

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Location

Campus, Varian 355

Speaker
August (Gus) Evrard (University of Michigan)

In the last decade, the astrophysical processes driving galaxy formation in a cosmological context at kpc scales have been incorporated, largely independently, into multiple codes developed by different simulation teams.

The probability distribution function (PDF) of cosmic density fluctuations: How to measure it? How to model it? What information does it contain?

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Location

Campus, Varian 355

Speaker
Oliver Friedrich (Kavli Institute for Cosmology Cambridge)

In this talk I will lead you through the highlights of a series of papers (Gruen++2018, Friedrich++2018, Friedrich&Uhlemann et al. in prep, Uhlemann&Friedrich et al. in prep) that promote an alternative framework of studying large scale structure data: analysis of the 1-point PDF of density fluctuations. The main difference between the PDF and 2-point correlation functions is readily explained: 2-point functions measure the variance of fluctuations as a function of scale, while the PDF measures all moments of the fluctuations at one scale.

Precision Cosmology with the Cosmic Microwave Background

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Location

Campus, Varian 355

Speaker
Sara Simon (University of Michigan)

The cosmic microwave background (CMB) provides unparalleled views into the early universe and its later evolution. Recent and ongoing experiments have contributed to our understanding of neutrinos, dark energy, and dark matter through measurements of large scale structure imprinted on the CMB and constrained the conditions in the early universe, tightly restricting inflationary and other cosmological models through measurements of CMB polarization.

Statistical Challenges in photometric redshift inference

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Location

Campus, Varian 355

Speaker
Markus Michael Rau (Carnegie Mellon University)

Observations from large area photometric surveys like LSST or DES will constrain cosmology to unprecedented precision. Deep wide-area imaging will provide observations for faint galaxy samples, for which traditional redshift calibration using spectroscopic data is very difficult.

Increased Hubble tension with a new measurement of the Hubble constant using strong lensing

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Location

Campus, Varian 355

Speaker
Anowar Shajib (UCLA)

The recent tension between early- and late-Universe measurements of the Hubble constant highlights the necessity for independent and precise probes such as the time-delay cosmography. The measured time-delays between the lensed images of a background quasar depend on the absolute physical scales in the lens configuration. Thus, they allow measurement of these scales to infer the Hubble constant, H_0.