Colóquios

Resumo: Recent studies of our motion with respect to the distribution of matter on large scales have found discrepancies in our peculiar velocity with respect to results obtained from the cosmic microwave background (CMB). These findings raise questions about the Cosmological Principle, a fundamental concept that suggests our velocity should be the same in both the CMB and matter reference frames. In this talk, I will explore the quasar luminosity function (QLF), which describes how quasars are distributed in terms of distance and brightness, and how different QLF models impact the strength of the kinematic dipole. I will also discuss how ignoring the dipole evolution over time leads to different results for our peculiar velocity. Finally, I will explain how this time evolution may provide opportunities to constrain cosmological parameters, with a particular focus on dark energy.

Resumo: Electric and magnetic dipoles play an important role in classical electromagnetism and quantum mechanics. They are even more significant in quantum field theory, since the first successful loop prediction of QED is precisely the anomalous (dipole) magnetic moment of the electron. More broadly, dipole operators frequently appear in theories beyond the standard model, where they can be probed using different techniques. In this colloquium, I will first summarize the important role that dipoles play in classical electromagnetism, quantum mechanics and quantum field theory; I will then describe two examples of theories beyond the Standard Model in which dipole operators are important for the phenomenology: "sterile dipoles" and "dark dipoles".