Lorentz Violation in Emergent Gravity and Its Cosmological Consequences

Abstract

We show that General Relativity and other geometrical theories can be viewed as a degenerate Otto cycle with only heat-exchange legs in emergent gravity. Including work-producing legs yields controlled violations of local Lorentz invariance and energy-momentum conservation, which produce late-time cosmological acceleration. Implications for the cosmological constant problem, structure formation and local observations are discussed.

Figures (2)

• Figure 1: Sketch of an infinitesimal Otto cycle in the $(N,\mu)$ and $(S,T)$ planes. GR and its geometric relatives arise from a degenerate cycle, obtained by collapsing the red legs to a point and retaining the blue legs (corresponding to the fluxes through $\mathscr{I}^{\mp}$). Adding the isentropic red legs leads to the proposed new theories, for which the heat in an out are not the same, and "chemical" work is done.
• Figure 2: Sketch of an infinitesimal Otto cycle in the $(N,\mu)$ and $(S,T)$ planes generating $W>0$ but assuming $\tfrac{\partial T}{\partial N}=\tfrac{\partial \mu}{\partial S}<0$, in contrast with Fig. \ref{['FigOtto']}. To obtain the corresponding cycles with $W<0$ one should reverse all arrows and swap labels 1 and 3 in this figure and in Fig. \ref{['FigOtto']}.