(topology) A theorem which (in one of its simplest forms) states that a continuous function from an n-dimensional unit cube (in ℝⁿ) to itself has a fixed point.

(quantum chromodynamics) In quantum chromodynamics with massless flavours, where the number of flavours is sufficiently small (i.e. small enough to guarantee asymptotic freedom, depending on the number of colours), an interacting conformal fixed point of the renormalization group where the value of the coupling is less than one (i.e. one can perform perturbation theory in weak coupling).

(mathematics) A formula that counts the fixed points of a continuous mapping from a compact topological space X to itself by means of traces of the induced mappings on the homology groups of X.

(proverbial) To deal with a problem or potential problem while conditions are favorable.