When: Wednesday, November 20, 2024 - Wednesday, November 13, 2024, 3:30 PM - 4:30 PMWhere: G.O. Jones - Common area
In my talk I will present the two ultra-large large-scale structure (uLSS) discoveries that I made in my PhD: the Giant Arc (GA) and the Big Ring (BR). Both uLSSs were found using the novel method of intervening MgII absorbers in the spectra of quasars. The observational and statistical analysis of the GA and BR raise important questions for both the Cosmological Principle (CP) and the standard cosmological model (LCDM). For example, the GA and BR both exceed the often-cited scale of homogeneity provided by Yadav (2010), are intriguing circular-type structures, and are both in the same cosmological neighbourhood --- in the same redshift slice at z~0.8 and separated by only ~12° on the sky.
I will discuss large-scale structure (LSS) studies in cosmology generally, provide an overview of the method of MgII absorbers for mapping LSS, present the analysis of the GA and BR, and lastly, suggest possible implications of the uLSS discoveries for cosmology. It may be that intriguing uLSSs, such as the GA and BR, are hinting at physics beyond the standard cosmological model; for example, we speculate that cosmic strings might provide a possible explanation.