Galaxies 2014, 2, 89-159; doi:10.3390/galaxies2010089 OPEN ACCESS galaxies ISSN 2075-4434 www.mdpi.com/journal/galaxies Article Thermodynamics of Rotating Black Holes and Black Rings: Phase Transitions and Thermodynamic Volume Natacha Altamirano 1;2, David Kubiznˇak´ 1, Robert B. Mann 1;3;* and Zeinab Sherkatghanad 3;4 1 Perimeter Institute, 31 Caroline St. N., Waterloo, ON N2L 2Y5, Canada; E-Mails:
[email protected] (N.A.);
[email protected] (D.K.); 2 Facultad de Matematica,´ Astronom´ıa y F´ısica, FaMAF, Universidad Nacional de Cordoba,´ Instituto de F´ısica Enrique Gaviola, IFEG, CONICET, Ciudad Universitaria, Cordoba´ 5000, Argentina 3 Department of Physics and Astronomy, University of Waterloo, Waterloo, ON N2L 3G1, Canada; E-Mail:
[email protected] 4 Department of Physics, Isfahan University of Technology, Isfahan 84156-83111, Iran * Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +1-519-882-1211. Received: 9 January 2014; in revised form: 6 February 2014 / Accepted: 7 February 2014 / Published: 3 March 2014 Abstract: In this review we summarize, expand, and set in context recent developments on the thermodynamics of black holes in extended phase space, where the cosmological constant is interpreted as thermodynamic pressure and treated as a thermodynamic variable in its own right. We specifically consider the thermodynamics of higher-dimensional rotating asymptotically flat and AdS black holes and black rings in a canonical (fixed angular momentum) ensemble. We plot the associated thermodynamic potential—the Gibbs free energy—and study its behavior to uncover possible thermodynamic phase transitions in these black hole spacetimes.