Beta-deformation
We will now consider the case of so-called beta-deformation.
Linearized beta-deformations transform in the following representation:
where the subindex means zero internal commutator;
has .
The nonlinear solutions were studied in:
O.Aharony, B.Kol, and S.Yankielowicz,
On exactly marginal deformations of SYM and type IIB supergravity
on
https://arxiv.org/abs/hep-th/0205090
It was shown that the renormalization of beta-deformation is again a beta-deformation, and the anomalous dimension is an expression cubic in the deformation parameter.
In our language this corresponds to the obstacle starting at . One would thing that the relevant cohomology group is:
But this cohomology group is zero, because
is finite-dimensional.
What actually happens is:
where is some infinite-dimensional extension of .
We will now explain this extension.