Final answer:
The given references do not provide sufficient information to answer what transition related to black hole jets Dr. Sivakoff has described, as the information provided pertains to broader cosmological theories and economic policies rather than specific astrophysical phenomena related to black holes.
Step-by-step explanation:
The question seems to relate to astrophysics and specifically to the behavior of black hole jets which are a feature in theoretical models of how black holes affect their surroundings. However, this specific query about Dr. Sivakoff and the transition that black hole jets can undergo does not seem to match with the provided reference information regarding cosmology and the large scale structure of the universe, such as the expansion due to dark energy, the oscillating theory of the universe, recession of galaxies, or fiscal policies in economics. Therefore, with the given information, it is not possible to definitively answer what transition Dr. Sivakoff states black hole jets can undergo. Accordingly, it would be necessary to look up Dr. Sivakoff's specific research or statements to find an accurate answer to the question.