Postdoctoral Research Associates
Advisor: David Hammer
Area of Study: Physics Education
I'm interested in what it is that instructors of University-level introductory science courses can do, in and out of class, to make more space for all student--to make sense of things, to articulate their own ideas, and to refine their own reasoning.
Through a project funded by the HHMI Inclusive Excellence Initiative, I coordinate regular meetings of Tufts instructors in the natural sciences in which the instructors get to practice listening to student thinking and help each other notice, in students' thinking, the productive beginnings of scientific practice.
Area of Study: Cosmology
What is the history of our Universe? What happened in its first seconds? What phenomena took place in the epochs which we cannot observe with our telescopes? What imprints could they have left behind?
These questions broadly define the motivation of my research. I am interested in understanding current cosmological observations and predicting new observable phenomena using a particle physics/beyond the Standard Model perspective. More specifically, these are some of the topics I have been working on: model building for cosmological inflation in string theory and in effective field theory; reheating after inflation; baryogenesis, primordial black holes and axions as dark matter candidates; phase transitions in the early Universe, including beyond the Standard Model scenarios for electroweak and Peccei-Quinn symmetry breaking, and their gravitational wave signatures.
Since joining the Institute of Cosmology at Tufts University, I have been working on ideas to reconcile early and late time determinations of the Hubble parameter, as well as on tunneling in quantum field theory.
Advisor: W. Anthony Mann
Area of Study: High Energy Physics
I'm interested in subatomic particles called "neutrinos," and specifically, what we can learn about the structure of fundamental forces from a peculiar phenomenon they experience called "neutrino oscillations." Unlike any of the other basic particles we know about—including the more familiar ones, like the electron, as well as the quarks that make up protons and neutrons—the three known types of neutrinos are simultaneously both stable (don't undergo radioactive decay) and yet likely to exchange their identities with each other while traveling along. The way that the neutrinos shuffle their "flavor" back and forth is directly related to how much mass they have (which, in contrast to decades of belief prior to the 1990s, has been conclusively determined to be nonzero, earning Kajita and McDonald the 2015 Nobel Prize in physics). The study of neutrino oscillations also offers some unique insights into the nature of the weak nuclear force, which is an important player in many other branches of physics. Understanding which mathematical symmetries the weak force obeys, and which it violates, for instance, may help us better answer one of cosmology's most important nagging questions, which is why the observable universe contains plenty of matter but has almost no detectable antimatter. Helping to decide whether neutrino oscillations violate charge-parity symmetry is one of the goals of the NOvA neutrino experiment, which I collaborate on.
The neutrino is a difficult probe to use, though, because it interacts incredibly rarely. This forces us to use extremely large detectors (NOvA's total mass is about 14,300 tons) to maximize the number of interactions we observe, and large detectors mean we can't exclusively use simple materials that are easy to understand mathematically (like hydrogen). High-quality simulation tools are essential to interpreting the data we collect and extracting the neutrino oscillation measurements we are interested in. I also collaborate on the GENIE neutrino interaction generator, which is a neutrino simulation program that uses predictive models for how neutrinos should interact with various kinds of matter from theoretical physicists. We combine these predictions with measurements from neutrino interaction experiments to produce simulations that are used in neutrino physics work worldwide, including in NOvA.