(astronomy) The time which light takes to traverse the mean distance of the Earth from the Sun.

(category theory) An adjunction whose unit and counit are both natural isomorphisms.

(mathematics) The second-order linear differential equation xy+(1-x)y'+ny=0.

Equipment used to supply power to charge an electric vehicle

(physics) an equilibrium in which a small disturbance causes it to move back to the original state

(physics) an equilibrium in which a small disturbance causes it to move further away from the original state

(mathematics) A matrix equation, used in control theory, of the form AX + XB = C. Given matrices A, B, and C, the problem is to find possible matrices for X.

Either of a pair of first-order nonlinear differential equations that are frequently used to describe the dynamics of biological systems in which two species interact, one as a predator and the other as prey.

(mathematics) A special kind of integral equation, having applications in demography, the study of viscoelastic materials, and actuarial science.

A rare mosquito-borne disease caused by a togavirus, affecting horses and humans in the Americas.