Title: “Unveiling New Physics beyond the Standard Model of Cosmology with Galaxies”

Abstract: “The standard model of cosmology has been a tremendous success, providing a robust framework for understanding the Universe. However, it leaves several fundamental questions unresolved. Growing tensions and anomalies in current datasets suggest the possibility of new physics beyond this paradigm. The distribution of galaxies encodes critical information about the origin and dynamics of the Universe. Ongoing and upcoming galaxy surveys offer unprecedented data volumes and number densities, opening exciting opportunities to search for tensions and anomalies. Fully exploiting this data requires advanced algorithms that go beyond the widely used 2-point statistics. In this talk, I will provide examples of how higher-order statistics can extract additional information and uncover unexpected features from the data. Anomalies such as parity violation on cosmological scales could offer new insights into the matter-antimatter asymmetry and the dynamics of the early Universe.” 

Forging a Multi-Messenger View of Supermassive Black Hole Binaries

Supermassive black hole binaries lurk deep within the cores of post-merger galaxies, and their identification represents the only key to unlock previously impossible probes of gravity, galaxy evolution, and the structure of the cosmos. While electromagnetic signatures probe plasma and gas in the environment around a binary, only pulsar timing arrays are currently sensitive to the low-frequency gravitational waves emitted directly by these slow-evolving giants. Pulsar timing array experiments have reached a critical turning point, and have recently announced that they have at last uncovered evidence of the stochastic gravitational wave background. The window to the gravitational-wave universe has been widened as we are now able to expand our view to include nanohertz gravitational wave frequencies, and will now turn our eye towards gravitational waves emitted directly by individual binary systems. Simultaneously, our electromagnetic capabilities to study the variable universe are on the brink of a new paradigm that will be opened by Rubin, Roman, and their dedicated surveys. In this talk, I will give an overview of electromagnetic, gravitational wave-, and multi-messenger studies of supermassive black hole binaries thus far. Then I will describe the possibilities for the road ahead, methods under development, and the next steps necessary to achieve a multi-messenger detection of a supermassive black hole binary and uncover the secrets of the variable universe.