Corinna Ulcigrai (born 3 January 1980, Trieste)[1] is an Italian mathematician working on dynamical systems.[2] With Krzysztof Frączek in 2013, Ulcigrai is known for proving that in the Ehrenfest model (a mathematical abstraction of billiards with an infinite array of rectangular obstacles, used to model gas diffusion) most trajectories are not ergodic.[1]