An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The optimum → gauge for steady fields, defined by: ∇.A = 0, where A is the → magnetic vector potential. Also called transverse gauge.

→ Coulomb; → gauge.

1) (n.) A standard of measure or measurement, size, or quantity.
2) Any of a wide variety of devices or instruments used for measuring a parameter or characteristic of an object, such as its dimension, quantity, or mechanical accuracy.
3) Physics: One of the family of choices for a constant in the expression of → potential energy in a central force field. Force is connected with potential energy by the relation F = - ∂U/∂r, U = ∫F.dr. The upper limit in the integral can be chosen arbitrarily. The potential energy is usually considered zero at infinity.
4) (v.) To determine the exact dimensions, capacity, quantity, or force of; measure.

From Fr. jauge "gauging rod," perhaps from Frankish galga "rod, pole for measuring;" cf. O.N. gelgja "pole, perch;" O.H.G. galgo; Lith. zalga "pole, perch;" Arm. dzalk "pole;" E. gallows; see below.

Gaz "a yard for measuring cloth; a length of 24 finger-breadths, or six hands; the tamarisk-tree," from Mid.Pers. gaz "tamarisk," may be of the same origin as gauge. In verbal form with kardan "to do, to make" (Mid.Pers. kardan; O.Pers./Av. kar- "to do, make, build;" Av. kərənaoiti "he makes;" cf. Skt. kr- "to do, to make," krnoti "he makes, he does," karoti "he makes, he does," karma "act, deed;" PIE base k^wer- "to do, to make").

A class of elementary particles that includes the gluon, photon, W⁺, W^-, and Z⁰ particles, each having an integral spin.

→ gauge; → boson.

The mathematical group associated with a particular set of gauge transformations.

→ gauge; → group.

The invariance of any field theory under gauge transformation.

→ gauge; → invariance.

A principle underlying the quantum-mechanical description of the three non-gravitational forces. It allows a system to behave in the same way even though it has undergone various transformations. The earliest physical theory which had a gauge symmetry was Maxwell's electrodynamics.

→ gauge; → symmetry.

A field theory in which it is possible to perform a transformation without altering any measurable physical quantity.

→ gauge; → theory.

A change of the fields of a gauge theory that does not change the value of any measurable quantity.

→ gauge; → transformation.

Same as the → Coulomb gauge.

→ transverse; → gauge.