Bulletin of the American Physical Society
Fall 2022 Meeting of the APS Eastern Great Lake Section and the Michigan Section of AAPT: Pushing Boundaries in Physics and Education
Volume 67, Number 16
Friday–Saturday, October 21–22, 2022; Lawrence Technological University, Southfield, Michigan
Session J04: Astro and Mathematical Physics |
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Chair: Cynthia Aku-Leh, ISciences Room: Lawrence Technological University S217 |
Saturday, October 22, 2022 8:15AM - 8:30AM |
J04.00001: Numerical Methods for Computing Forward and Inverse Laplace Transform For discrete and continuous signals Yueyang Shen, Yupeng Zhang, Ivo D Dinov Effective integral transformations enable simplification of mathematical modeling and computational inference by mapping the original signal representation into a more manipulatable state space. Designing specialized data maps transforming (probabilistic) state representations capitalizes on contemporary computational advances and relates to well-known application scenarios, such as kernel machines, MDP transition dynamics modeling and policy optimizations, and generative modeling. A well-known classical example is the Laplace transform, which maps the subspace of differential equations to the space of algebraic equations, where the solution can be obtained by inverting the algebraic equation. The Laplace transform (LT) and its inverse (ILT) represents a family of integral transforms that have direct applications in contemporary data science, statistical inference, and probabilistic modeling. However, practical computational challenges inhibit their utilization on complex or implicit functions, noisy observations, and incomplete data. |
Saturday, October 22, 2022 8:30AM - 8:45AM |
J04.00002: Dynamics of General Extreme Mass Ratio Inspiral Resonances Harrison G Blake, Makana Silva, Christopher M Hirata Extreme mass ratio inspirals (EMRIs) are scenarios in which a smaller body spirals into a black hole at least ten thousand times more massive. When the Laser Interferometer Space Antenna (LISA) launches, it will be able to pick up the gravitational waves (GWs) coming from EMRI events where the larger body is a supermassive black hole (SMBH) [1], such as in the galactic center. However, said galactic centers are crowded, leading to perturbations of the EMRI system and, therefore, changing their emitted GWs [2]. The most significant change comes when an object further out from the inspiral enters into a resonance with the smaller EMRI body [2]. Our goal with this project is to develop a method of quantifying the effects of the resonance on the inner body's orbit and classifying the types of resonance encounters for any set of possible orbits, expanding on prior research to generalize to non-circular orbits [3]. We do this by simulating potential orbits for both objects, identifying resonance encounters, and then determining whether the resonance is a crossing or a capture. The method is able to find resonance encounters across the entire evolution of the EMRI system and categorize the type of resonance at each encounter. The proper identification of resonances can be used to describe the dynamics near galactic centers we observe and to distinguish perturbations caused by resonances from perturbations caused by deviations from general relativity [4]. |
Saturday, October 22, 2022 8:45AM - 9:00AM |
J04.00003: Using Color Gradients to Study the Inside-Out Formation of Disk Galaxies at 0.8 ≤ z ≤ 1.0 Karmellah R Buttler, Laura M DeGroot In this study, we investigated the inside-out galaxy disk formation theory by deriving U - V rest-frame color gradients of a sample of 408 disk galaxies at 0.8 ≤ z ≤ 1.0. Using HST WFC3 images of the GOODS-N region from the CANDELS and UVCANDELS surveys, U - V color maps were created using PSF convolved postage stamps of galaxies in both the F275W and F125W filters, and surrounding objects in the images were masked out for analysis. Color gradients were analyzed through radial profiling using concentric annuli with widths of 0.5 kpc out to a full radius of ∼25 kpc. We find that 98.8% of the 408 galaxies have negative gradients, 45.3% of which had entire color profiles < 0.5 mag indicating that they are likely dominated by young stars, and 53.5% had profiles that had positive centers (> 0.5 mag centrally) and grew negative with radius. Our results suggest at least that an outside-in disk formation is not supported and at most that an inside-out disk formation is possible. Another potential conclusion is that there are fewer old stars in the galactic disk as radius from the center increases. The remaining 1.2% of galaxies had unusually shaped profiles. In the future, a determination of each galaxy's full radius is necessary to separate the galaxy's faint edge from the background. |
Saturday, October 22, 2022 9:00AM - 9:15AM |
J04.00004: Hybrid Equations of State for Neutron Stars with Hyperons and Deltas Alexander Clevinger, James Corkish, Veronica Dexheimer, krishna P aryal
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Saturday, October 22, 2022 9:15AM - 9:30AM |
J04.00005: A single-unified and mathematically-derived formula of Asymmetry Theory for the Doppler Effect, Cosmological Red-shift and Cherenkov radiation Qian Chen The well-established principle of the constancy of the velocity of light can be mathematically represented with the general equation O(to)-S(ts)=c(to-ts). Based solely on this equation without including any other assumptions, a comprehensive set of ground-breaking results was derived solely through strict mathematics, which is named “Asymmetry Theory”. In this theory, one single formula explains the fundamental nature of the Doppler Effect, Cosmological red-shift and Cherenkov radiation, which is the time scaling factor between the light emission time and observation time. |
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