Hannah Cairo

Cairo was born in Nassau, Bahamas.^[1] Cairo is transgender.^[2] She began studying mathematics using online lessons from Khan Academy, and finished calculus by age 11.^[3] During the COVID-19 pandemic, she began participating in the Berkeley Math Circle (BMC) remotely.^[4] After moving to the United States, she continued to attend university-level mathematics lectures at the University of California, Berkeley, including courses taught by mathematician Ruixiang Zhang.^[1]

In fall 2025, having skipped the standard bachelor's and master's degrees, she is expected to begin her PhD studies at the University of Maryland,^[4] focusing on Fourier restriction theory.^[2]

While studying under Zhang, Cairo began working on the Mizohata–Takeuchi conjecture, which had remained unresolved since the 1980s.^[5] Initially aiming to prove the conjecture, she instead constructed a counterexample that disproved it.^[4] Her work involved using fractals and other tools and originally resulted in a more complex counterexample before finding a simpler example after reformulating the problem in frequency space.^[6]

Her findings were published in the preprint titled "A Counterexample to the Mizohata–Takeuchi Conjecture" and uploaded to the arXiv preprint server on February 10, 2025.^[7] Later that year, she presented her work at the 12th International Congress on Harmonic Analysis and Partial Differential Equations in El Escorial, Spain.^[4] Media described her as one of the youngest mathematicians to resolve a major open problem.^{[1][4][8][9][3][10]}

• Jean Bourgain
• Elias M. Stein
• Robert Strichartz
• Alexander Volberg

• Cairo, Hannah Mira (2025). "A Counterexample to the Mizohata–Takeuchi Conjecture". arXiv:2502.06137 [math].