* Introduction to resonant light matter interaction (coherent and incoherent scattering, Rabi oscillations, Mollow triplets)
* Origin of antibunching in resonance fluorescence (L. Hanschke et al. Phys. Rev. Lett. 125, 170402 (2020))
* Doubly-dressed Mollow triplets (C. Gustin et al. Phys. Rev. Research 3, 013044 (2021)
* Dynamic Mollow triplets from Janes-Cummins systems (K. Fischer et al. Nature Photonics 10, 163–166 (2016))
* Dynamic Mollow triplets from two-level systems (K. Boos et al. arXiv:2305.15827 (2023) – accepted at PRL)

.Scalar quantum field theories can possess metastable vacuum states which decay through thermal and quantum fluctuations. In space, the decay of the metastable vacuum proceeds through the creation and subsequent expansion of bubbles containing a new phase, which coalesce and eventually complete the phase transition. Vacuum decay is a non-perturbative and non-linear dynamical problem, making it the perfect candidate for quantum simulators. Understanding this process has phenomenological implications for early Universe cosmology, including observables such as a stochastic gravitational wave background, meaning there may be novel ways to use quantum simulators to make predictions for observational cosmology. In this talk I will first describe theoretical work developing observables for vacuum decay, including nucleation site correlation functions and bubble nucleation pre-cursors. I will then describe experimental efforts within the Quantum Simulators for Fundamental Physics consortium to develop analog quantum simulators of vacuum decay with cold atomic gasses. Such experiments will allow us to empirically test early Universe physics in tabletop experiments.

We construct the phase space of a spherically symmetric causal diamond in (d+2)-dimensional Minkowski spacetime. Utilizing the covariant phase space formalism, we identify the relevant degrees of freedom that localize to the d-dimensional bifurcate horizon and, upon canonical quantization, determine their commutators. On this phase space, we find two Iyer-Wald charges. The first of these charges, proportional to the area of the causal diamond, is responsible for shifting the null time along the horizon and has been well-documented in the literature. The second charge is much less understood, being integrable for d ≥ 2 only if we allow for field-dependent diffeomorphisms and is responsible for changing the size of the causal diamond.

Big Bang Nucleosynthesis (BBN) is a powerful tool for probing both new physics and LCDM, and complements analyses utilizing the Cosmic Microwave Background (CMB) and results from particle experiment. I will provide two examples of BBN probes of BSM models. I will then discuss new kinds of analyses that can be performed with the recently-released fast and differentiable BBN code LINX. In particular, LINX can be used to perform full BBN+CMB joint analyses at a level of sophistication that has never been achieved before, even in LCDM analyses.

Recent advances in General Relativity point toward unanticipated, and dynamic, relations between ultracompact objects and the universe they inhabit. The possibility for strongly gravitating systems, like astrophysical black holes (BHs) and their embedding cosmology, to directly interact has been dubbed "cosmological coupling." We focus on recent results from the DOE Stage IV Dark Energy (DE) Spectroscopic Instrument (DESI), which strongly suggest that DE is dynamical. Using typical empirical models for the cosmic star-formation rate density as a proxy to BH production, we show that the DESI-inferred time-evolution of DE is consistent with cosmologically coupled stellar-collapse BHs as the source of DE. The predicted cosmological expansion rate today, H_0 = 69.94 +/- 0.81 km/Mpc/s, is in excellent agreement with H_0 = 69.58 +/- 1.58 km/Mpc/s recently reported by the Chicago-Carnegie Hubble Program using Cepheid, Tip of the Red Giant Branch, and J-Region Asymptotic Giant Branch stellar distance-ladder calibrations. With DESI Redshift Space Distortions and Year 3 datasets on the horizon, we highlight exciting prospects for further observational confrontation in the near term.