Background:
After reading about Carter constant and symmetries in GR, I became interested in Killing tensors.
I tried reading this paper by Alan Barnes, Brian Edgar and Raffaele Rani, discussing conformal Killing tensors. I have some trouble understanding the crux of the paper.
Question:
Is there a general way to construct Killing tensors, if the Killing vectors are known?
How would I do this?
Are there any Killing tensors that can not be constructed from Killing vectors?
Initial guess/motivation for the question:
Initially, I thought Killing tensors could just be formed via $K_{\mu \nu}=k_\mu k'_\nu$, where $K_{\mu \nu}$=Killing tensor, $k_\mu,k'_\nu$=Killing vectors. After reading the above paper, I am no longer sure. The paper discusses conformal Killing tensors and vectors, which may be the source of my confusion.