Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: graph theory, this word describes a path in an undirected graph that meets each vertex only once such as that of the edge graph of a dodecahedron; such paths are described using the Bondy-Chvatal theorem. Systems described by this adjective include dynamical billiards and gravitational orbits as the forces in these systems are independent of the velocities. These systems are often formulated with a namesake vector field that exists on a symplectic manifold or more generally on an arbitrary Poisson manifold. In physical chemistry, the Dyall form of this operator involves the sum of the products of orbital energies and spin-traced operators for a two-electron system, while the more commonly used form of this operator is equal to negative h-bar squared over twice the mass times the Laplacian plus the potential energy of the system and corresponds to the observable of the total energy of that system. FTP, identify this ubiquitous adjective in math and sciences that is named after a 19th century Irish physicist and mathematician with first and middle names William Rowan.
A:
Science