  We recently introduced a new method for simulating collisional gravitational
N-body systems with approximately linear time scaling with $N$, based on the
Multi-Particle Collision (MPC) scheme, previously applied in Plasma Physics. We
simulate globular clusters with a realistic number of stellar particles (at
least up to several times $10^6$) on a standard workstation. We simulate
clusters hosting an intermediate mass black hole (IMBH), probing a broad range
of BH-cluster and BH-average-star mass ratios, unrestricted by the
computational constraints affecting direct N-body codes. We use either single
mass models or models with a Salpeter mass function, with the IMBH initially
sitting at the centre. The force exerted by and on the IMBH is evaluated with a
direct scheme. We measure the evolution of the Lagrangian radii and core
density and velocity dispersion over time. In addition, we study the evolution
of the velocity anisotropy profiles. We find that models with an IMBH undergo
core collapse at earlier times, the larger the IMBH mass the shallower, with an
approximately constant central density at core collapse. The presence of an
IMBH tends to lower the central velocity dispersion. These results hold
independently of the mass function. For the models with Salpeter MF we observe
that equipartition of kinetic energies is never achieved. Orbital anisotropy at
large radii appears driven by energetic escapers on radial orbits. We measure
the wander radius. Among the results we obtained, which mostly confirm or
extend previously known trends that had been established over the range of
parameters accessible to direct N-body simulations, we underline that the
leptokurtic nature of the IMBH wander radius distribution might lead to IMBHs
presenting as off-center more frequently than expected, with implications on
observational IMBH detection.
