Simon Fraser University
SFU Cosmology Seminars

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Tuesday, 22 October 2019, 14:30 in P8445B

Prof. Arif Babul (UVic)

Cosmology with galaxy clusters

Clusters of galaxies are the largest, most massive gravitationally bound objects in the Universe. They are also the most recent of the cosmic objects to form. In the currently accepted models of cosmic structure formation, the evolution of the number density of these galaxy clusters over the recent (cosmologically speaking) past depends sensitively on the parameters describing the large-scale geometry and the expansion history of the universe. For this reason, galaxy clusters are regarded as important cosmological probes. The first step in using clusters as cosmological probes involves involves starting with a large, well-defined sample of galaxy clusters and "weigh them". Here, I will discuss what "weighing them" entails and highlight some of the challenges involved. I will then summarize the outcome of the cosmological analysis, and compare the resulting values of the key cosmological parameters to those derived from the studies of the cosmic microwave background. Interestingly, the two do not agree with each other! And, this troubling tension remains unresolved. I will conclude by speculating about the implications of, and potential resolutions, of this tension.

Seminars in 2019:

2019-09-10 14:30 in P8445B - Gabor Kunstatter (University of Winnipeg/SFU): What can quantum gravity tell us about the beginning and end of time?
2019-09-17 14:30 in P8445B - Andrei Frolov (SFU): Dust is everywhere
2019-10-08 14:30 in P8445B - Douglas Scott (UBC): Evaporating evidence for Hawking points
2019-10-22 14:30 in P8445B - Arif Babul (UVic): Cosmology with galaxy clusters
2019-11-19 14:30 in P8445B - Richard Shaw (UBC): Probing Dark Energy with CHIME
2019-11-26 14:30 in P8445B - Joanna Woo (SFU): Primer on machine learning for astronomy
2019-12-03 14:30 in P8445B - Ludovic Van Waerbeke (UBC): Axion Quark Nuggets: a candidate for baryonic, cold and strongly interacting dark matter
2020-01-20 15:00 in P8445B - Francesc Ferrer (Washington University): Gravitational wave signals of early universe axion dynamics
2020-02-14 14:30 in C9000 - Katie Mack (North Carolina State University): Dark matter: a cosmological perspective (physics colloquium)
2020-02-26 14:30 in P8445B - Paul Wiegert (University of Western Ontario): Interstellar asteroids and comets: what are they and where do they come from?
2020-02-28 14:30 in C9000 - Sara Ellison (University of Victoria): Clash of the Titans: Galaxy mergers in the nearby Universe (physics colloquium)
2020-05-12 12:00 in Zoom - Levon Pogosian (SFU): Relieving the Hubble tension with primordial magnetic fields
2020-05-19 12:00 in Zoom - José Tomas Gálvez Ghersi (University of Mississippi): Numerical renormalization group-based approach to secular perturbation theory
2020-06-02 12:00 in Zoom - Leo Stein (University of Mississippi): Gravitational-wave tests of GR with simulations of beyond-GR theories
2020-06-16 12:00 in Zoom - Andrei Frolov (Simon Fraser Univeristy): Primordial non-Gaussianity from preheating
2020-07-02 14:30 in Zoom - Jack Gegenberg (University of New Brunswick): Collapse of a rotating shell in 3+1 dimensions (special seminar)
2020-07-07 12:00 in Zoom - Joanna Woo (Simon Fraser Univeristy): Machine learning as a tool for astrophysics
2020-07-28 12:00 in Zoom - José Tomas Gálvez Ghersi (University of Mississippi): A fixed point for black hole distributions

[ See complete seminar archives | iCal feed ]

Modified by Andrei Frolov <frolov@sfu.ca> on 2023-11-01