The role of the irreducible mass in repetitive Penrose energy extraction processes in a Kerr black hole

R. Ruffini, C. L. Bianco, M. Prakapenia +3

The concept of the irreducible mass ($M_{\mathrm{irr}}$) has led to the mass-energy ($M$) formula of a Kerr black hole (BH), in turn leading to its surface area $S=16\pi M_{\mathrm{irr}}^2$. Th…