unconstrained complex provided the constraint (2.18) is the
only condition imposed on Γ. However, if we are dealing
with a real linear superfield,
ð
¯
D
2
− 4RÞL ¼ 0;
¯
L ¼ L; ð2:22Þ
then the constraints are solved [12] in terms of an uncon-
strained real prepotential V,
L ¼ i
¯
D
α
D
α
V;
¯
V ¼ V; ð2:23Þ
which is defined modulo gauge transformations of the form
δV ¼ λ þ
¯
λ; J λ ¼ 0;
¯
D
α
λ ¼ 0: ð2:24Þ
If L is super-Weyl primary, then Eq. (2.17) tells us that the
dimension of L is þ1. In this case it is consistent to
consider the gauge prepotential V to be inert under the
super-Weyl transformations [12], δ
σ
V ¼ 0.
Let us assume that the background curved superspace
allows the existence of a real transverse linear superfield
W
αðnÞ
¼
¯
W
αðnÞ
,
¯
D
β
W
βα
1
…α
n−1
¼ 0; D
β
W
βα
1
…α
n−1
¼ 0: ð2:25Þ
Then it is automatically conserved,
D
βγ
W
βγα
1
…α
n−2
¼ 0: ð2:26Þ
in accordance with (2.4b). The super-Cotton tensor W
αβ
is
an example of such supermultiplets. If W
αðnÞ
is super-Weyl
primary, then its dimension is equal to ð1 þ n=2Þ,in
accordance with (2.17). As will be shown in the next
subsection, a solution to (2.25) in terms of an unconstrained
prepotential exists for every conformally flat superspace.
C. Conformal gauge superfields
Let n be a positive integer. A real symmetric rank-n
spinor superfield H
αðnÞ
is said to be a conformal gauge
supermultiplet if (i) it is super-Weyl primary of dimension
ð−n=2Þ,
δ
σ
H
αðnÞ
¼ −
n
2
σH
αðnÞ
; ð2:27Þ
and (ii) it is defined modulo gauge transformations of
the form
δ
λ
H
αðnÞ
¼
¯
D
ðα
1
λ
α
2
…α
n
Þ
− ð−1Þ
n
D
ðα
1
¯
λ
α
2
…α
n
Þ
; ð2:28Þ
with the gauge parameter λ
αðn−1Þ
being unconstrained
complex. The dimension of H
αðnÞ
in (2.27) is uniquely
fixed by requiring the longitudinal linear superfield g
αðnÞ
¼
¯
D
ðα
1
λ
α
2
…α
n
Þ
in the right-hand side of (2.28) to be super-
Weyl primary. Indeed, the gauge parameter g
αðnÞ
must be
neutral with respect to the R-symmetry group Uð1Þ
R
since
H
αðnÞ
is real, and then the dimension of g
αðnÞ
is equal to
ð−n=2Þ, in accordance with (2.14).
Starting with H
αðnÞ
one can construct its real descendant
W
αðnÞ
ðHÞ¼AH
αðnÞ
, where A is a linear differential
operator involving D
A
, the torsion superfields and their
covariant derivatives, with the following properties:
(1) W
αðnÞ
is super-Weyl primary of dimension
ð1 þ n=2Þ,
δ
σ
W
αðnÞ
¼
1 þ
n
2
σW
αðnÞ
: ð2:29Þ
(2) The gauge variation of W
αðnÞ
vanishes if the super-
space is conformally flat,
δ
λ
W
αðnÞ
¼ OðW
ð2Þ
Þ; ð2:30Þ
where W
ð2Þ
is the super-Cotton tensor (2.7).
(3) W
αðnÞ
is divergenceless if the superspace is con-
formally flat,
¯
D
β
W
βαðn−1Þ
¼ OðW
ð2Þ
Þ;
D
β
W
βαðn−1Þ
¼ OðW
ð2Þ
Þ: ð2:31Þ
Here OðW
ð2Þ
Þ stands for contributions containing
the super-Cotton tensor and its covariant derivatives.
In general, W
αðnÞ
ðHÞ is uniquely defined modulo a
normalization and contributions involving the super-
Cotton tensor (2.7). The primary superfields W
αðnÞ
ðHÞ
may be interpreted as linearized higher-spin super-Cotton
tensors in supergravity; see also the next subsection.
D. Linearized conformal higher-spin supergravity
in conformally flat backgrounds
So far the supergravity background has been completely
arbitrary. In the remainder of this section we assume that
the background curved superspace M
3j4
is conformally
flat,
W
αβ
¼ 0: ð2:32Þ
Then each primary superfield W
αðnÞ
ðHÞ, with n ¼ 1; 2; …,
is gauge invariant,
δ
λ
W
αðnÞ
¼ 0; ð2:33Þ
and obeys the conservation equations (2.25). These proper-
ties and the super-Weyl transformation laws (2.27) and
(2.29) imply that the action
3
3
The super-Weyl transformation of the superspace density is
δ
σ
E ¼ −σE.
HUTOMO, KUZENKO, and OGBURN PHYS. REV. D 98, 125004 (2018)
125004-6