Speaker
Description
The universe is a vast place, but what if this universe was just one of many embedded in a greater multiverse? How can we look for such a multiverse? In this paper, we develop our understanding of a multiverse and how bubble universes can exist. We discuss the existing literature on the topic and develop an understanding of the possibilities of other bubble universes colliding with our own universe. We discuss a theoretical thermal profile that mimics the mathematical structure of de Sitter - de Sitter bubble collisions, which we can use to look for bubble universe collisions in the Cosmic Microwave Background (CMB) sky. Through this paper, we develop a three part pipeline to look
for these signatures in the 2021 Planck CMB data. We first simulate a set of CMB maps consisting of the CMB ’backgrounds’ and bubble collision signatures incorporated into them. We then carry out a Blob Detection algorithm on these maps, conducting a parameter sensitivity study to validate our pipeline outputs to establish a set of threshold requirements defining a collision signature. We also apply a Simple Statistical Model onto the simulated maps to see how well our algorithm can recreate input parameters. Lastly, we apply our detection algorithm and statistics model onto the Planck data to look for any regions in the sky that would match our threshold requirements to be counted as a bubble collision signature. We find no features in the Planck data that meet our threshold requirements, but we discuss in depth the detection of 14 maximal features and the possibilities of these being potential bubble collision signature candidates. We also discuss the need for further study with increased sensitivity, and comment on improvements for future works.
