This project is mathematical research in Banach space theory, which treats such matters as the convergence of series and integrals in an infinite-dimensional setting. It has historical connections to more concrete applied subjects because, for instance, solutions to differential equations are often conveniently thought of as inhabiting an appropriate Banach space of functions. More specifically, Professor Lin will study ultraproducts of certain function spaces, asymptotic properties of Banach spaces, and issues of type and cotype, particularly weak Hilbert spaces.