<strong>Paper Title</strong><br>
Geometrothermodynamics of The Cosmological Constant<br>
<br>

<strong>Abstract</strong><br>
We study the properties of black holes with cosmological constant in the framework of geometrothermodynamics.
We consider in particular the case of the Schwarzschild-anti-de-Sitter black hole, and show that the
corresponding fundamental equation is a generalized homogeneous function only if the cosmological constant is assumed to
be a thermodynamic variable. We analyze the geo- metric properties of the equilibrium space and show that the presence of
the cosmological constant changes drastically the stability properties and the phase transition structure of the black hole.
Keywords- Black holes, phase transitions, thermodynamics, geometrothermodynamics PACS numbers: 05.70.Ce; 05.70.Fh;
04.70.-s; 04.20.-q