The electron–positron phase of the Future Circular Collider (FCC-ee) will offer an opportunity to significantly improve measurements of the Standard Model parameters. One possible measurement is the Higgs–electron coupling, which requires a year of dedicated run time. In this talk, I will first summarize the experimental strategy and projected sensitivities for this program at FCC-ee, and how...
We propose a minimal and natural dark-sector framework in which dark matter is composed of magnetic monopoles coupled to a light axion field. Through the Witten effect, the axion background induces electric charge on the monopoles, turning them into dyons that in turn modify the axion potential. This monopole-dependent axion mass provides a simple, radiatively stable mechanism for dark-sector...
The QCD axion, which solves the strong CP problem and constitutes a dark matter candidate, remains one of the most motivated signals of physics beyond the Standard Model. In the canonical scenario, the QCD axion mass-coupling relation fixes the interaction strength below the reach of most experiments, which target lighter or more strongly coupled axions. However, no fundamental principle...
Finite density corrections to the lighter-than-QCD axion can invert the effective axion potential, sourcing a non-trivial axion field inside dense objects. In this talk, I will present the first numerical study of the complete dynamics of the lighter-than-QCD axion in a neutron star in 1+1 general relativity, extending the region of analysis of the lighter-than-QCD axion to low-mass axions...
The high densities in the early Universe provide a unique laboratory to constrain couplings between feebly interacting particles, such as dark matter and neutrinos. I will introduce a model where neutrinos get their mass from a small diagonal coupling to ultralight dark matter (ULDM), and how to consistently use cosmology, namely Big Bang Nucleosynthesis (BBN), to constrain it. In particular,...
As one of NASA’s proposed future Astrophysics Probe missions, the Advanced X-ray Imaging Satellite (AXIS) is designed to improve the sensitivity and spatial resolution of the Chandra X-ray Observatory. AXIS aims to deliver low-background, arcsecond imaging over a broad 0.3–10 keV energy range, featuring an effective area of 3600 cm$^2$ at 1 keV and 830 cm$^2$ at 6 keV across a 450 arcmin$^2$...
Complex dark sectors are models where a 'sector' of new particles with intra-sector interactions are used to extend the Standard Model. Motivated by theoretical considerations such as the Hierarchy Problem, these models generically also provide dark matter candidates. In this talk I will discuss a range of complex dark sectors and how the properties of the gauge group can effect astrophysical...
Active Galactic Nuclei (AGNs) are among the most powerful multi-messenger sources in the universe, emitting high-energy neutrinos and electromagnetic radiation. Recent observations from IceCube and complementary gamma-ray and X-ray telescopes aid in precise modeling of these extreme environments. In this talk, I will discuss how AGNs—natural sites of intense particle acceleration—can also...
