Physics Research
The dark matter mystery
Dark Matter
One of the largest open unanswered questions in physics is: What is dark matter? Dark matter constitutes 80% of the matter in our universe however we have never seen it. Numerous astrophysical observations have concluded that the visible matter alone cannot explain the motion of the stars or galaxies. If one assumes that the luminous matter (all matter that interacts with, or gives off light) constitutes all of the mass in each galaxy, our galaxies should be flying apart because there simply isn't enough gravitational matter to hold galaxies together. To reconcile this discrepancy between the amount of luminous matter and the amount of total gravitational matter, physicists hypothesize a massive particle that is not luminous and therefore would account for this difference in mass. This unseen gravitational source is the dark matter.
Axions
One dark matter candidate is the axion. The axion is a hypothetical particle initially introduced to solve another open problem in physics: the strong CP problem. The strong CP problem is related to the observation that we see more matter than antimatter in our universe. The axion, if observed, could both solve the strong CP problem and explain dark matter observations. Because axions are so light, abundant, and unreactive, we can think of them as a persistent, background, nearly undetectable field.
DMRadio
The Dark Matter Radio (DMRadio) is a suite of experiments leading the search for axion dark matter. By tuning resonant elements like a radio, we can pickup axion signals of different frequencies (ie. particle masses). Broken into three distinct experimental phases, the DMRadio experiment will hunt for axions with masses between 10 peV and 1 μeV. These experiments detect axions through their coupling to a strong magnetic field where an axion would drive a current through a pickup structure which is read out with quantum sensors. Presently, DMRadio-50L is being built at Stanford. As a collaborator on DMRadio, I design and build both hardware and software components of our detector.
ABRACADABRA
A Broadband/Resonant Approach to Cosmic Axion Detection with an Amplifying B-field Ring Apparatus (ABRACADABRA) is demonstrator experiment searching for axion dark matter with a toroidal magnet. As the predecessor to DMRadio, ABRACADABRA ran at MIT in broadband mode for seven years. Currently, I am working on an upgrade that allows us to simultaneously search for axion dark matter and gravitational waves. This parallel search utilizing one detector is the first of its kind and could pave the way for increased experimental capabilities of particle physics detectors.
