Abstract:
Gravity being the manifestation of the curvature of spacetime can create regions which are inaccessible to a class of observers. An example of such a region is the event horizon of black objects which acts as a one way causal boundary. The thermodynamics of space time horizons is believed to be a crucial input to understand the quantum dynamics of gravity. The basis of this thermodynamic analogy is the area theorem by Hawking which asserts that the area of the event horizon can not decrease in any classical process. The proof of the area theorem depends on both the validity of Einstein's equation as well as on the cosmic censorship hypothesis. A natural question in this regard could be to ask whether the thermodynamic properties of space time horizons can be generalized beyond general relativity? In this article, we will focus on the "area theorem" of black hole thermodynamics and discuss various possible generalization to higher curvature gravity. We will also discuss how the generalization of the area theorem beyond general relativity leads to various constraints in the couplings of higher curvature terms.