  Recently a debate has arisen over which of the two distinct parts of the
Fermi surface of Sr2RuO4, is the active part for the chiral p-wave
superconductivity. Early theories proposed p-wave pairing on the two
dimensional gamma-band, while a recent proposal focuses on the one dimensional
(alpha,beta) bands whose nesting pockets are the source of the strong
incommensurate spin density wave (SDW) fluctuations. We apply a renormalization
group theory to study quasi-one dimensional repulsive Hubbard chains and
explain the form of SDW fluctuations, reconciling the absence of long range
order with their nesting Fermi surface. The mutual exclusion of p-wave pairing
and SDW fluctuations in repulsive Hubbard chains favors the assignment of the
two dimensional gamma-band as the source of p-wave pairing.
