(geometry) A certain invariant of complex projective surfaces.

plural of Gromov-Witten invariant

(mathematics) A rational number that, in certain situations, counts pseudoholomorphic curves meeting prescribed conditions in a given symplectic manifold. They have applications in string theory.

plural of Donaldson-Thomas invariant

(algebraic geometry) Given a compact moduli space of sheaves on a Calabi-Yau threefold, its Donaldson-Thomas invariant is the virtual number of its points, i.e., the integral of the cohomology class 1 against the virtual fundamental class.

(physics, mathematics) a feature of objects or laws that do not change if length scales (or energy scales) are multiplied by a common factor.

A pendulum for carrying from station to station to be oscillated at each, so as to fix the relative acceleration of gravity.

plural of invariable pendulum

(astronomy) The orbital plane passing through a planetary system's barycenter (center of mass) perpendicular to its angular momentum vector.

plural of invariable plane