Energy extraction and particle acceleration around a rotating black hole in quintessence

We study motion and collision of particles in the gravitational field of rotating black hole immersed in quintessential dark energy characterized with the quintessential parameter omega(q) is an element of (-1;-1/3) governing the equation of state of the dark energy, and the dimensionless quintessential field parameter (c) over tilde. We focus on the acceleration of particles due to collisional processes and show how the center of mass energy depends on the quintessential field parameter (c) over tilde. We also make comparison of the obtained results to the collisional energetics of quintessential static black holes demonstrating the crucial role of the rotation parameter a in the particle acceleration. Finally we study the dependence of the maximal value of the efficiency of energy extraction through Penrose process for rotating black hole with quintessential field parameter (c) over tilde. It is found that quintessence field decreases the energy extraction efficiency through Penrose process and when the parameter (c) over tilde vanishes one can get the standard value of the efficiency coefficient for the Kerr black hole as eta similar to 21 %.