KICP Seminars & Colloquia, Current and Future

Seminar schedule for Current (Summer 2018) & Future Quarters
June 29, 2018
Friday noon seminar
Jo Bovy
The University of Toronto
Mapping the Milky Way in 6D with Gaia   [Abstract]
July 5, 2018
Open Group seminar
Sebastian Bruggisser
Electroweak Baryogenesis through varying Yukawas in Composite Higgs models   [Abstract]
July 9, 2018
Astronomy Special Seminar
Vasiliki Pavlidou
University of Crete
The Drunken Trek of Ultra-High-Energy Cosmic Rays Through The Magnetic Field of the Milky Way   [Abstract]
July 18, 2018
Special seminar
Rachel Rosen
Columbia University
Black Holes for Massive Gravitons   [Abstract]
July 26, 2018
Open Group seminar
Santiago Casas
CEA Paris-Saclay
Dark Energy with Euclid   [Abstract]
August 15, 2018
Special seminar
Marius Millea
Optimal CMB Lensing Reconstruction and Improved Constraints on Primordial Gravitational Waves   [Abstract]
October 3, 2018
Wednesday colloquium
Silvia Galli
Institut D'Astrophysique de Paris
October 10, 2018
Wednesday colloquium
Brian Keating
UC San Diego
Fundamental Physics with the Simons Observatory   [Abstract]
KICP Colloquia and Astronomy & Astrophysics Colloquia: Unless otherwise noted, all talks are held in ERC 161 at 3:30 PM on Wednesdays. A reception will be held following the talk in the ERC 401 (KICP Colloquia) and in Hubble Lounge (ERC 501) (Astronomy & Astrophysics Colloquia).

  • October 3, 2018 | 3:30 PM | ERC 161 | Wednesday colloquium
    Silvia Galli, Institut D'Astrophysique de Paris
  • October 10, 2018 | 3:00 PM | ERC 161 | Wednesday colloquium
    Fundamental Physics with the Simons Observatory
    Brian Keating, UC San Diego

    Note: Reception at 4:30 PM in the ERC 401.

    The Simons Observatory is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. I will describe the scientific goals of the experiment, motivate its design, and forecast its performance. The Simons Observatory will measure the temperature and polarization anisotropy of the cosmic microwave background with arcminute resolution over approximately 40% of the sky in six frequency bands: 27, 39, 93, 145, 225 and 280 GHz. In its initial phase, three small-aperture (0.5-meter diameter) telescopes and one large-aperture (6-meter diameter) telescope will be fielded. These instruments will host a total of 60,000 cryogenic bolometer detectors. I will discuss some of the key science goals of the Simons Observatory, including the characterization of primordial fluctuations, determination of the number of relativistic species, and measuring the mass of neutrinos. I will also discuss other tests of fundamental physics -- some of which may be best measured using Cosmic Microwave Background observations such as the ones we are embarking upon.

KICP Friday noon seminar: Unless otherwise noted, all talks are held in ERC 401 at Noon on Fridays.

  • June 29, 2018 | 12:00 PM | ERC 401 | Friday noon seminar
    Mapping the Milky Way in 6D with Gaia
    Jo Bovy, The University of Toronto

    One of the main goals of Gaia, a new astrometric satellite mission, is to provide an empirical measurement of the distribution of stars in the 6+N dimensional space of position, velocity, age, mass, elemental abundances, color, magnitude, etc.. Knowledge of this empirical distribution will allow the formation, evolution, and dynamics of the Milky Way to be strongly constrained. I will give an overview of the Gaia mission and discuss novel methods to map the Milky Way in position and velocity using the billion-star Gaia catalog. I will then discuss results on the stellar content and dynamics of the solar neighborhood from applying these techniques to Gaia's first and second data release. I will also discuss the implications of the structure in the velocity distribution in the extended solar neighborhood observed in Gaia's second data release.


  • July 18, 2018 | 3:30 PM | ERC 445 | Special seminar
    Black Holes for Massive Gravitons
    Rachel Rosen, Columbia University

    In this talk I will review the status of black hole solutions for theories in which the gravitational force is mediated by a massive spin - 2 particle. I will present the arguments that such black holes must necessarily be time - dependent and I will discuss the implications for black hole mechanics.
  • August 15, 2018 | 1:00 PM | ERC 401 | Special seminar
    Optimal CMB Lensing Reconstruction and Improved Constraints on Primordial Gravitational Waves
    Marius Millea, IAP

    The next generation of CMB experiments are slated to measure the CMB polarization to noise levels and angular resolutions never before probed. One of the most exciting and revolutionary possibilities for this data would be a discovery of the non-zero tensor-to-scalar ratio $r$, i.e. the first detection of the background of gravitational waves produced by inflation. These gravitational waves are detectable via their impact on CMB B-mode polarization, however the B-modes are also significantly contaminated by the effects of gravitational lensing. Removing this lensing-induced B-mode foreground (called "delensing") will be necessary to obtain the tightest possible constraints on $r$. While at present-day noise levels, so-called "quadratic estimator" techniques have been massively successful in estimating and removing the lensing contamination, they become statistically sub-optimal at the noise-levels of even very near-future experiments. It is an open question how to improve upon them, and an exciting one because the potential is to shrink the error bar on $r$ by factors of a few, maybe turning a few-sigma hint of gravitational waves into a full blown discovery! In this talk, I will discuss an optimal Bayesian delensing method which we've developed to solve this problem. In the spirit of this being very much ongoing work, I will tell you about both successes we have had but also roadblocks and outstanding issues. Ultimately, this method can yield not only improved constraints on $r$, but also yield better reconstructions of the lensing potential which can be used in cross-correlations with various other low-redshift probes of structures.


  • July 5, 2018 | 3:00 PM | PRC 201 | Open Group seminar
    Electroweak Baryogenesis through varying Yukawas in Composite Higgs models
    Sebastian Bruggisser, DESY

    Varying Yukawas open new possibilities for electroweak baryogenesis. In this talk I will start by introducing varying Yukawas as a source of CP-violation and explain how baryogenesis can be successful in this framework. I will then present a realization of this paradigm in Composite Higgs models with partial compositeness. Composite Higgs models are, apart from the usual benefits, particularly compelling for this scenario as they feature an intimate link between flavour and Higgs physics. We will see that baryogenesis can be successful in these models if the confinement phase transition happens at the same time as the electroweak phase transition. I will identify regions in parameter space where this is fulfilled and I will compute the baryon yield of those models.
  • July 26, 2018 | 12:00 PM | ERC 401 | Open Group seminar
    Dark Energy with Euclid
    Santiago Casas, CEA Paris-Saclay

    Euclid is an ESA medium-class mission expected to launch in 2022 that will map the geometry of the Universe by imaging 109 galaxies and measuring 107 galaxy redshifts in 15000 square degrees of the sky. This will provide us detailed information about the accelerated expansion, the evolution of large-scale structure and the matter-energy content of the Universe up to a redshift of about z ≈ 2. In this talk, I will review how the main probes of Euclid, namely galaxy clustering and weak lensing, will be able to constrain theories beyond the standard cosmological ΛCDM model and how we will be able to pin down the equation of state of dark energy with about 1% precision. Galaxy clustering measures mainly the movement of tracers along geodesics, while weak lensing is an almost direct mapping of the gravitational potentials at large scales. Using both of these observables, we can obtain valuable information about the growth of perturbations and the geometrical quantities of the Universe and therefore constrain the properties of General Relativity. Since the measurements of Euclid will also give insights on the properties of dark matter and neutrinos at cosmological scales, I will also show how we can measure non-standard couplings between matter species and dark energy and how we can give tight constraints on many alternative theories of gravity.

KICP's Thunch: KICP Cosmology Lunch (Thunch) Weekly on Thursdays, Noon, ERC 401A.

Please join us for an informal lunch discussion, led by KICP fellows, of recent news and papers in cosmology. Topics range from experiment and observations to theory in all areas of KICP science. To submit or view papers for this week's Thunch please visit the Thunch website.



  • July 9, 2018 | 12:00 PM | ERC 501 | Special Seminar
    The Drunken Trek of Ultra-High-Energy Cosmic Rays Through The Magnetic Field of the Milky Way
    Vasiliki Pavlidou, University of Crete

    Cosmic rays are charged so that the magnetic field of the galaxy acts as a distorting lens to our view of the ultra-high-energy cosmic ray sky. I will discuss how we can reconstruct this lens and use it to our advantage to investigate both where cosmic rays come from, and what their composition is.