Classical-physics applications for Finsler bb space

The classical propagation of certain Lorentz-violating fermions is known to be governed by geodesics of a four-dimensional pseudo-Finsler $b$ space parametrized by a prescribed background covector field. This work identifies systems in classical physics that are governed by the three-dimensional version of Finsler $b$ space and constructs a geodesic for a sample non-constant choice for the background covector. The existence of these classical analogues demonstrates that Finsler $b$ spaces possess applications in conventional physics, which may yield insight into the propagation of SME fermions on curved manifolds.Comment: 8 pages, 2 figures, accepted for publication in Physics Letters

INDIRECT UTILITY FUNCTIONS AND TESTABLE CONDITIONS

We develop testable hypotheses for utility maximization given risk averse producers based on a general specification of the utility function. This is a direct expansion of the model posed by Pope (1978). Empirical tests using production data with a translog specification indicate that utility maximization does not always hold.Research Methods/ Statistical Methods,

Essays in Pro-social Behavior

This dissertation examines individuals\u27 actions to improve social outcomes when unrecoverable investments are necessary. Situations involving non-pecuniary and pecuniary investments are considered. In the former, the prerequisite of real effort - a non-pecuniary, unrecoverable investment - is examined when said effort determines an individual\u27s ability to procure their preferred social outcome. Theoretical predictions over an individual\u27s effort provision are based on their revealed preferences for the social distribution of wealth according to the general axiom of revealed preference (GARP). Laboratory experiments reveal that individuals\u27 effort provisions do not support the assumption of stable preferences (transitivity) of wealth distribution. Specifically, individuals who reveal a preference for egalitarian outcomes do not exert enough real effort toward said outcomes when all of the wealth can be distributed directly to them. In the latter, pecuniary situation, auction formats that require all bidders to pay their bid (i.e., all-pay auctions) are studied as a way of funding public goods, specifically in the context of charity auctions. An innovative theoretical variation of the war of attrition is designed. This variation requires bidders to make unrecoverable upfront investments in the auction in order to participate, and the amount of one\u27s investment dictates how much one can potentially bid in the auction. In addition, an empirical analysis of this theoretical variation is provided via laboratory experiments. These experiments seek to highlight the bidder-specific and mechanism-specific characteristics that may lead to greater success in charitable fund-raising. The results suggest that auction mechanisms with an incremental bidding design outperform mechanisms with a lump-sum bidding design

Direct and Indirect Searches for Axion Dark Matter

The majority of the matter in the Universe is non-luminous and unaccounted for by any known particle, making the unknown nature of dark matter one of the most urgent problems in fundamental physics. Amidst a broad landscape of particles proposed to explain the dark matter, axions have emerged as a particularly well-motivated candidate as they naturally arise in extensions of the Standard Model and can simultaneously reproduce the observed dark matter abundance while solving other outstanding mysteries in particle physics. Despite this, axions have remained largely unprobed, and new insights and innovative approaches are required to carefully test the axion dark matter hypothesis. This thesis aims to advance prospects for axion detection by identifying how axion signals may appear, developing optimized searches for these signals, and implementing robust analysis strategies. I will begin by showing how simulations of axion production in the early universe can direct search efforts toward the best-motivated mass range for axions that solve the Strong textit{CP} Problem related to the absence of a neutron electric dipole moment in quantum chromodynamics. I will then discuss the development of rigorous analysis frameworks for axion direct detection and their application to the search for axion dark matter with the ABRACADABRA detector. Lastly, I will show how astrophysical observations with textit{X}-ray and radio telescopes can be used in novel searches for axion dark matter. This thesis contributes to an increasingly comprehensive search program that will either discover or exclude axion dark matter in the coming years.PHDPhysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169679/1/fosterjw_1.pd

X-ray Searches for Axions from Super Star Clusters

Axions may be produced in abundance inside stellar cores and then convert into observable X-rays in the Galactic magnetic fields. We focus on the Quintuplet and Westerlund 1 super star clusters, which host large numbers of hot, young stars including Wolf-Rayet stars; these stars produce axions efficiently through the axion-photon coupling. We use Galactic magnetic field models to calculate the expected X-ray flux locally from axions emitted from these clusters. We then combine the axion model predictions with archival Nuclear Spectroscopic Telescope Array (NuSTAR) data from 10 - 80 keV to search for evidence of axions. We find no significant evidence for axions and constrain the axion-photon coupling $g_{a\gamma\gamma} \lesssim 3.6 \times 10^{-12}$ GeV$^{-1}$ for masses $m_a \lesssim 5 \times 10^{-11}$ eV at 95\% confidence.Comment: 8+18 pages, 3+21 figures, version published in PRL. Supplementary Data at https://github.com/bsafdi/axionSS