Speaker: | Noam Libeskind (AIP) |
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Title: | Cosmography and dynamics of the Local Universe |
Date (JST): | Thu, Mar 21, 2024, 13:30 - 15:00 |
Place: | Seminar Room A |
Abstract: |
What does the Universe around us look like and how do we map it? Galaxies and dark matter are not distributed uniformly but instead form a complicated multi scale network known as the cosmic web. It is notoriously difficult to map such a complicated structure. For one, galactic light is a biased tracer of matter. It’s susceptible to a myriad of optical effects including various forms of distortion. Secondly, the measurements themselves are error prone and its is a challenge to finesse a signal out of a sea of noise. Last but not least, the universe is expanding and evolving making it conceptually difficult to map a dynamic topography. I will describe how maps of the cosmic web can be made based on incomplete, heterogeneous and error filled data using state of the art computational models. I will describe how some of the features we see in the cosmographic maps are mirrored in the galaxy distribution and how these cosmological reconstructions can be used to run constrained simulations of this - not a generic - universe. These simulations can shed light on galaxy formation as a whole and the formation of the Milky Way and Local group specifically. Lastly I will discuss how galaxies, dark matter haloes and planes of satellite galaxies are oriented with respect to the cosmic web. Time permitting I will also show the first ever evidence that cosmic filaments spin, thereby demonstrating that angular momentum and vorticity can be generated on unprecedented scales. |