1301.0009 (Jarmo Mäkelä)

Cosmological Constant as a Free Thermodynamical Variable    [PDF]

Jarmo Mäkelä

We consider a possibility that the cosmological constant may not be a constant, but a free thermodynamical variable. To this end we construct a microscopic model of a spacelike two-sphere just inside of the cosmological horizon of the de Sitter spacetime. In our model the spacelike two-sphere in question is assumed to consist of discrete constituents, each of them contributing to the two-sphere an area, which is in an integer times a constant. Using our model we obtain a thermodynamical equation of state for the cosmological constant. Our equation of state implies that the cosmological constant has a certain positive lower bound, which depends on the number of the constituents of the two-sphere. If the two-sphere is assumed to be in thermal equilibrium with the cosmic microwave background, one finds that the cosmological constant is inversely proportional to the square of the temperature of the background.

View original: http://arxiv.org/abs/1301.0009