In our research, we will focus on trying to explain the dynamics of certain particles known as pseudo scalar mesons. These kinds of particles are charged both under electromagnetism as well as under the strong interaction coupling. Due to the presence of these dual couplings, the particles will interact both via the strong and the electromagnetic interaction. To assess the dynamics of these kinds of interacting particles, one can either resort to using approximate lattice constructions of the full theory to calculate its properties, or construct tractable effective field theories. In this vein, this work will compare a non-relativistic effective field theory, which perturbativley takes into account the electromagnetic interaction, and reproduce such results through a lattice approximation. In the work, I find that both the effective field theory and the lattice construction are shown to be in agreement for two to three body meson interactions.

Star formation at the outer extremities of the Milky Way takes place under conditions much different from those in the rest of the Galaxy, giving us a window into how the process differs in a low-density, low-metallicity region. The Outer Scutum-Centaurus (OSC) spiral arm is the most distant molecular spiral arm in the Galaxy, lying about 15 kpc from the center of the Galaxy. In this study, we use the VLA radio array to observe 12 HII regions in the OSC, all of which had no previously existing continuum data. HII regions are areas of ionized hydrogen around massive stars and are the brightest objects in the radio spectrum across the Milky Way, making them perfect laboratories to study star formation in the outer Galaxy. These OSC HII regions represent the most distant known high-mass star formation regions in the Milky Way and give us an excellent laboratory for studying those processes in a low-density, low-metallicity environment. Our data let us identify radio continuum data for 7 HII regions in the OSC, as well as establish upper limits for the RMS associated with the other 5 observed nondetections. By assuming a single ionizing star for each region, we assign spectral types from O9 to O5.5 to these sources. Combined with existing data, we identify a total of 12 HII regions in the OSC Arm with continuum and spectral data. Further research would involve re-observing our nondetections to identify data for what are likely B-type ionizing sources. Obtaining meaningful data for those nondetections would allow us to classify more stars powering HII regions in the region, increasing the amount of information known about star formation in the extreme conditions of the OSC and potentially revealing new information about how O-type and B-type stars form differently in the same unique environment.

Proxima b, the nearest potentially habitable exoplanet to the Solar System, has likely experienced significant change in its orbit and rotation over time due to tidal interaction with its host star and perturbations from its recently-confirmed companion, Proxima c. A possible threat to Proxima b's habitability is that it may have become a synchronous rotator, with a permanent dayside and nightside. To explore this possibility, we used the VPLanet software suite to simulate the system for a 7 billion year time period and examined how its orbit and rotation evolved with time. As the orbital planes of the two planets are currently unknown, we considered many configurations for the system, running several thousand simulations in total. We find that the time elapsed before Proxima b becomes a synchronous rotator is heavily dependent upon the initial configuration of the system. These results suggest that, due to the interplay of tidal dissipation and planet-planet gravitational interactions, Proxima b may have a complex dynamical history that impacts the likelihood of present-day habitability.

Extreme precipitation events have the potential to threaten physical infrastructure, property, and human lives, and are predicted to become heavier due to climate change. Understanding past, present, and future precipitation is important in analyzing how precipitation risks change spatially and temporally. The observational record, from which point precipitation frequency estimates such as NOAA Atlas-14 are derived, is limited by its lack of spatial coverage and it represents just one realization of past climate. When using a high-resolution large ensemble global climate model, we have multiple realizations of climate, consistent spatial coverage, and the added benefit of being able to incorporate climate change scenarios into precipitation risk analysis. Here, we use the GFDL (Geophysical Fluid Dynamics Laboratory) 50-km horizontal atmospheric resolution global SPEAR (Seamless System for Prediction and EArth System Research) 30-member ensemble to analyze how U.S. 24-hour precipitation extremes at various return periods change over the 1921-2100 time period. We quantify extreme precipitation risks across the U.S. and locally under different climate change scenarios (SSP2-4.5, SSP5-8.5, and natural forcings alone). With the large ensemble, we are also able to explore methodology and uncertainties in characterizing extreme precipitation risks.

Ice cores provide unique records of past climate, including chemical deposits from volcanic events, for up to 800,000 years before present. In this project we examine sulfate concentrations in five different ice cores in Antarctica. Sulfate measurements from deeper in an ice core are at risk of diffusion altering the chemical concentration. We define any sulfate concentration exceeding a prominence threshold of two standard deviations above the mean as a volcanic event. We track how the volcanic signals differ from one another, and evolve with depth (age), by finding the amplitude, width, and total area under each peak. By taking a variety of measurements of each volcanic signal, we can then compare similar signals across ice cores. Using the change in duration of volcanic events, we were able to infer a considerably lower diffusivity than the only previously published estimate, suggesting less alteration of the sulfate signal than originally expected. Understanding how mechanisms in the ice change the sulfate record allows for a more accurate interpretation and clearer understanding of Earth's past climate.