[File:BIsAPseudovector.svg|thumb|right|A loop of wire (black), carrying a
current I, creates a
magnetic field B (blue). If the position and current of the wire are reflected across the plane indicated by the dotted line, the magnetic field it generates would
not be reflected: Instead, it would be reflected
and reversed. The position of the wire and its current are vectors, but the magnetic field
B is a pseudovector.]] In
physics and
mathematics, a
pseudovector (or
axial vector) is a quantity that transforms like a
vector under a proper
rotation, but in three dimensions gains an additional sign flip under an
improper rotation such as a
reflection. Geometrically it is the opposite, of equal magnitude but in the opposite direction, of its
mirror image. This is as opposed to a
true or
polar vector, which on reflection matches its mirror image.
