  We calculate the anisotropic signal associated with the coupling of a
three-form with an Abelian vector gauge field. In the simplest examples of
three-form inflation the amplification of the vector fluctuations is
exponential; this makes it almost certain that a large anisotropy will develop,
severely constraining the viability of the coupling.

Cosmology and Nongalactic Astrophysics;High Energy Physics - Phenomenology