quadrupole
Sign in to saveA quadrupole or quadrapole is one of a sequence of configurations of things like electric charge or current, magnetic fields, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.
Article
9 sectionsContents
- Mathematical definition
- Examples {{Anchor|electric quadrupole}}
- Electric quadrupole
- Magnetic quadrupole
- Gravitational quadrupole
- Generalization: higher multipoles
- See also
- References
- External links
A quadrupole or quadrapole is one of a sequence of configurations of things like electric charge or current, magnetic fields, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.
==Mathematical definition== The quadrupole moment tensor Q is a rank-two tensor—3×3 matrix. There are several definitions, but it is normally stated in the traceless form (i.e. Q_{xx} + Q_{yy} + Q_{zz} = 0). The quadrupole moment tensor has thus nine components, but because of transposition symmetry and the zero-trace property, in this form only five of these are independent.