A Borel subgroup of a connected linear algebraic group is a maximal connected solvable closed subgroup. Over an algebraically closed field, all Borel subgroups are conjugate. The invertible upper triangular matrices form a Borel subgroup of the general linear group.
Borel Subgroup
See also
Algebraic Group, General Linear Group, Solvable GroupExplore with Wolfram|Alpha
References
Humphreys, J. E. Linear Algebraic Groups. New York: Springer-Verlag, 1975.Cite this as:
Weisstein, Eric W. "Borel Subgroup." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/BorelSubgroup.html