Leszek Roszkowskis
Director of the Astrocent Institute in Warsaw

Abstract

The Copernican Revolution — the heliocentric model of the Universe introduced by Nicolaus Copernicus — is considered as one of the most significant achievements in the history of science. And yet, it luckily happened despite many obstacles and even then it could have become unnoticed and forgotten. This year marks the 550th anniversary of the birth of Nicolaus Copernicus which gives us additional motivation to have a closer look at his highly extraordinary life and achievement.

Affiliation: Astrocent, Nicolaus Copernicus Astronomical Center and National Centre for Nuclear Research Poland

Timbits, coffee, tea will be served in STI B before the colloquium.

Kiyoshi Masui
Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research

Abstract

For more than a decade, enigmatic extragalactic flashes called fast radio bursts (FRBs) have defied a definitive explanation for their origin. In addition, the unique properties of FRBs make them promising probes of both cosmology and the distribution of gas on intergalactic scales. The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is the only radio telescope capable of instantaneously observing hundreds of square degrees with the sensitivity of a 100-meter scale aperture. As a result, its transient search instrument, CHIME/FRB, has detected thousands of FRBs, increasing the known sample by an order of magnitude. I will give an overview of CHIME/FRB's most recent results, where observations of particular sources and statistical analyses of the FRB population are starting to reveal the nature of this mysterious phenomenon. I will then describe an effort to augment CHIME/FRB's capabilities by adding Outrigger telescopes, which will be located across North America and will precisely localize FRB sources using very long baseline interferometry. The resulting large sample of localized FRBs will allow for detailed measurements of the large-scale distribution of baryons in the universe, providing precise constraints on feedback processes in galaxy evolution.

Timbits, coffee, tea will be served in STI B before the colloquium.

Dr. Masui will be available to meet with graduate students and postdocs (12-1pm on Monday) and undergraduate students (12-1 on Tuesday) with lunch for up to 20 people each day.  Stirling 201.

Jim Peebles
Princeton University, 2019 Nobel Prize in Physics co-recipient

Abstract

Our standard cosmology passes an abundance of well-checked tests that make a convincing case that it is a good approximation to what happened as our universe expanded and cooled from a hot and dense early state. But the theory is incomplete. We cannot say how the dark energy and dark matter of our cosmology fit in standard particle theory, and we cannot even even find tight measures of the properties of these dark components; we still rely on simple models. A way forward is to collect evidence of problems with cosmology that might yield hints to help improve the theory. I will discuss examples.

Timbits, coffee, tea will be served in STI A before the colloquium.