My research focuses on the theoretical, computational, and experimental aspects of searching for axion dark matter candidates. I also contribute to several other topics that I find fascinating, which you can read some about below.
If you would like to learn more about my work, collaborate, or have questions about the banner equations pictured at the top of this page, then please contact me via the email address below.
Axion Dark Matter:
Axions are a proposed fundamental constituent of our universe that are suspected to be the dark matter, and possibly also solve other lingering issues in fundamental physics. Axions are light, expected to weigh less than a billionth of an electron apiece. But, to be the dark matter and to seed the formation of galaxies and other structures in modern cosmology, axions must exist in great density; at least a trillion would be flowing through your screen right now! As a result of this tight packing, axion dark matter is expected to form a "Bose-Einstein condensate", meaning that the axions are overlapping on a quantum level. There has been a great deal of effort to determine if our universe has axions, and their type. Techniques range from looking at indirect evidence through astrophysical sources like stars & black holes & galaxies & even the cosmic microwave background, to direct detection in the laboratory. As a graduate student, I helped commission and operate the premier Axion Dark Matter eXperiment, ADMX, a direct detection experimental search during its inaugural run as part of the DOE's Generation-2 dark matter searches. ADMX searches for axions using an apparatus called a cavity haloscope that converts axions into light waves inside a cavity about the size of a few kitchen microwave ovens. The microwaves in the typical countertop oven (~1,000 Watts) are much more powerful than what we would expect from an axion signal, closer to yocto-Watts = 0.000,000,000,000,000,000,000,001 Watts. Observing such a weak signal is a great challenge. In my current research, I develop new haloscope designs using quantum sensors -- which use quantum features like entanglement -- to more effectively search for the axion.
Another element of my work in dark matter involves understanding what the axion signal would look in a haloscope in order to distinguish it from other sources of microwaves. The axion signal when viewed in frequencies is expected to be very narrow, much like radio or broadcast television stations, and a cavity haloscope can be though of as searching to tune in to the 'axion station'. Large simulations performed on supercomputers can be used to depict the formation of our galaxy and its dark matter, from which we can build an approximation of the axion 'tune.' Conversely, after the axion is found, we can listen in to what the axion signal has to say about the formation of the Milky Way. I am especially interested in the quantum features of the axion Bose-Einstein condensate and designing haloscopes to better pick up their unique signatures.
(Quantum) Information Theory:
What constitutes information and its role in our understanding of natural and engineered systems is a topic of interest both in basic science and applied research. My research into information theory currently takes two forms:
Quantum information applied to sensing very feeble signals from dark matter (see previous topic)
Classical information as applied to time series signal processing, which can be used to robustly detect, localize and isolate a signal's data transmission properties by tracking the independence and correlations between elements (see CV).
Superluminal Travel within Relativity Theory:
Hyper-fast (as in faster than light) solitons within modern theories of gravity have been a topic of energetic speculation for the past three decades. One of the most prominent critiques during this time of compact mechanisms of superluminal motion within general relativity is that the geometry must largely be sourced from a form of negative energy density, though there are no such known macroscopic sources in particle physics. The past several years (since 2020) have produced multiple new warp-drive-like solutions to general relativity and its sibling approach to gravity Einstein-Cartan theory that do away with negative energy requirements, pushing closer to testability. My research in this area has been to find increasingly realistic warp-drive-like solutions to hyper-fast transportation, including lowering the so-far astronomical energy requirements to bring testable solutions to the human technological scale.
The road to developing superluminal transportation is likely to be a difficult one, but humans may not be the first to try. It is possible that one or more extra-terrestrial intelligence, perhaps even within our own galaxy, may have succeeded in creating warp drives or something similar. In a recent paper, a collaborator and I posit that operating these devices may emit (techno-)signatures in the form of light waves, gravitational waves, or massive particles able to be detected by telescopes or other sensitive instruments. We are in the early days of exploring what these tchno-signatures may look like an how to search for them.
Physically-Motivated Action Principles:
The action principle is a cornerstone of modern physics, providing a concise means of expressing classical and even quantum dynamics. This principle is made even stronger by the consideration of symmetries of the action. Emmy Noether's two theorems on this topic revolutionized our consideration of fundamental physics more than a century ago, and there is still much to be learned from them now.
This simple pairing of symmetry and action may be able to tell us a great deal more than we already know. The action principle, given the proper environment and physical symmetries, may be capable of describing the physical forces and their relation to the nature and existence of matter. Such wording could be used to describe many attempts at unifying physics in the past century, but instead of exhausting an inflated model space and wrapping away the unobserved elements behind compactifications and other energy scale barriers, I am motivated to pursue a unified field theory via a handful of objectivity principles that have been staring us in the face yet have been largely overlooked such as Noether's second theorem, and that favors complimentarity to compactification when simplified to the scales of our everyday lives.
Ultra-Hyperbolic Equations:
Collections of partial differential equations can be broken down into four different classes: elliptic, parabolic, hyperbolic, and ultra-hyperbolic. The first three are seen in commonly idealized physical systems like electrostatics (Poisson's: elliptic), non-relativistic quantum mechanics (Schroedinger's: parabolic), and the motion of sound waves in media (hyperbolic). These classes are well posed as boundary value or initial value problems. The last class, ultra-hyperbolic, are not well posed as they have multiple time-like characteristic directions and may have many solutions arising about a given set of initial data. The task of describing dynamics modeled by such equations could be seen as significantly disadvantaged. However, I am interested in the structure of these equations because of their solution degeneracies. I would like to better understand the structure of these degeneracies with the aim of finding a novel approach to quantum theory.
(Side note: relativity theory on space with multiple time and multiple space dimensions would circumvent the constancy of the speed of light, possibly permitting superluminal travel without an instrument such as a warp drive.)