Let G be a connected complex semisimple Lie-group, T a maximal torus and B a Borel subgroup containing it. Let phi:GrightarrowG/B denote the projection.
Given a representation (theta,V) of B, we can define a G-equivariant holomorphic vector bundle over the flag variety X:=G/B by
GtimesBV:=(GtimesV)/(g,v)sim(gb−1,theta(b)v),forallbinB.
Its sheaf of sections mathcalI(theta) may be described as the holomorphic functions
mathcalI(theta)(U)=f:phi−1(U)rightarrowVmidf(gb−1)=theta(b)f(g).
G acts on a section by (gf)(x)=f(g−1x).
An integral weight lambda of T gives a character chilambda of B. Let thetaotimeschilambda denote the tensor product of the representations theta and chilambda.
Suppose (theta,V) is the restriction of a representation (pi,V) of G, then the associated (G-equivariant) vector bundle is trivial (i.e. isomorphic to XtimesV with (g,(x,v))mapsto(gx,pi(g)v)). Is the identity
mathrmHi(X,mathcalI(thetaotimeschilambda))simeqmathrmHi(X,mathcalI(chilambda))otimesV
as G or mathfrakg-modules correct?
Background/Motivation
I have been reading about the Borel-Weil theorem lately, and
Edit:
This question arose from an attempt to fix a mistake in a book.
The identity is indeed correct and I believe I have found the error elsewhere.
Thanks Chuck and Jim!
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