Ejemplo:
Gauge TheoryGauge theory studies
principal bundle connections, called
gauge fields, on a
principal bundle. These connections correspond to fields, in physics, such as an electromagnetic field, and the
Lie group of the
principal bundle corresponds to the symmetries of the physical system. The
base manifold to the
principal bundle is usually a four-dimensional
manifold which corresponds to space-time. In the case of an electromagnetic field, the symmetry group is the
unitary group . The other two groups that arise in physical theories are the
special unitary groups and . Also, a
group representation of the symmetry group, called internal space, gives rise to an
associated vector bundle.
Actually,the
principal bundle connections which minimize an energy
functional are the only ones of physical interest. For example, the
Yang-Mills connections minimize the
Yang-Mills functional. These connections are useful in
low-dimensional topology. In fact, in
Donaldson theory, the collection of Yang-Mills connections gives topological invariants of the
base manifold .
SEE ALSO: Donaldson Theory,
Group Representation,
Lie Group,
Manifold,
Principal Bundle,
Seiberg-Witten Equations,
Vector BundleThis entry contributed by
Todd RowlandREFERENCES: Friedman, R. and Morgan, J. W. (Eds.).
Gauge Theory and the Topology of Four-Manifolds. Providence, RI: Amer. Math. Soc., 1998.
Naber, G.
Topology, Geometry, and Gauge Fields. New York: Springer-Verlag, 2000.
CITE THIS AS:
Rowland, Todd. "Gauge Theory." From
MathWorld--A Wolfram Web Resource, created by
Eric W. Weisstein.
http://mathworld.wolfram.com/GaugeTheory.html