My work made mathematics more general and/or abstract. I put the definite integral on a firmer basis with a generalization now called the Riemann integral. In 1851 I invented a new way to show functions of complex numbers on a plane and developed fundamental ideas of topology to handle such representations. In 1854 I addressed the foundations of geometry in spaces of n dimensions, suggesting a new form of non-Euclidean geometry that later became the geometry of Einstein's general theory of relativity. In 1859 I made a conjecture about a complex function called the zeta function that remains among the main unresolved issues of mathematics.
