  The correlation between interstellar turbulent speed and local star formation
rate surface density, Sigma_SFR, is studied using CO observations in the PHANGS
survey. The local velocity dispersion of molecular gas, sigma, increases with
Sigma_SFR, but the virial parameter, alpha_vir, is about constant, suggesting
the molecular gas remains self-gravitating. The correlation arises because
sigma depends on the molecular surface density, Sigma_mol, and object cloud
mass, M_mol, with the usual molecular cloud correlations, while Sigma_SFR
increases with both of these quantities because of a nearly constant star
formation efficiency for CO. Pressure fluctuations with Delta Sigma_SFR are
also examined. Azimuthal variations of molecular pressure, Delta P_mol, have a
weaker correlation with Delta Sigma_SFR than expected from the power-law
correlation between the total quantities, suggesting slightly enhanced SFR
efficiency per molecule in spiral arms. Dynamical equilibrium pressure and star
formation rate correlate well for the whole sample, as P_DE~Sigma_SFR^1.3,
which is steeper than in other studies. The azimuthal fluctuations, Delta
P_DE(Delta Sigma_SFR), follow the total correlation P_DE(Sigma_SFR) closely,
hinting that some of this correlation may be a precursor to star formation,
rather than a reaction. Galactic dynamical processes correlate linearly such
that Sigma_SFR~(Sigma_gas R)^(1.0\pm0.3) for total gas surface density
Sigma_gas and galactic dynamical rates, R, equal to kappa, A, or Omega,
representing epicyclic frequency, shear rate A, and orbit rate Omega. These
results suggest important roles for both feedback and galactic dynamics.
