Horowitz's work spans nuclear theory, astrophysics, and computational modeling.
Neutron-star matter and the equation of state Horowitz has made contributions to understanding dense nuclear matter and the internal structure of neutron stars. His large-scale molecular-dynamics simulations demonstrated that neutron-star crust may be "10 billion times stronger than steel," a finding highlighted in multiple science-news outlets and press releases. His simulations predicted exotic phases of neutron-star crust known as
nuclear pasta, including shapes described as "waffles," "lasagna," and "spaghetti," which have been covered in the science media. These studies indicate that nuclear-pasta phases may be among the strongest materials in the universe, with implications for neutron-star oscillations, crust breaking strain, and potential gravitational-wave emission. Horowitz's theoretical and phenomenological work on the equation of state of dense matter has contributed to neutron-star structure studies that interface nuclear-physics models with astronomical observations and gravitational-wave constraints.
Parity-violating electron scattering Horowitz played a theoretical role in the
PREX (Lead Radius Experiment) collaboration, which used parity-violating electron scattering to measure the neutron-skin thickness of lead-208. • weak probes of nuclear structure, • and neutrino transport in astrophysical environments. His work on nuclear pasta, neutron-star crust physics, and neutrino interactions has also been covered in mainstream popular-science outlets and university press releases. == Awards ==