Related papers: Evaluating the Wald Entropy from two-derivative te…
We derive exact relations to all orders in the $\alpha'$ expansion for the charges of a bound system of heterotic strings, solitonic 5-branes and, optionally, a Kaluza-Klein monopole. The expressions, which differ from those of the…
In this paper we apply the entropy function formalism to the two-dimensional black hole which come from the compactification of the heterotic string theory with the dilaton coupling function. We find the Bekenstein-Hawking entropy from the…
Recently, Verlinde has suggested a novel model of duality between thermodynamics and gravity which leads to an emergent phenomenon for the origin of gravity and general relativity. In this paper, we investigate some features of this model…
It is by now clear that the naive rule for the entropy of a black hole, {entropy} = 1/4 {area of event horizon}, is violated in many interesting cases. Indeed, several authors have recently conjectured that in general the entropy of a dirty…
We derive new bounds on higher-dimension operator coefficients in four-dimensional Einstein-Maxwell theory. Positivity of classically-generated corrections to the Wald entropy of thermodynamically stable, rotating dyonic black holes implies…
We derive black hole entropy based on the near-horizon symmetries of black hole space-times. To derive these symmetries we make use of an $(R,T)$-plane close to a Killing horizon. We identify a set of vector fields that preserves this plane…
We propose a new entropy construct that generalizes the Tsallis, R\'enyi, Sharma-Mittal, Barrow, Kaniadakis, and Loop Quantum Gravity entropies and reduces to the Bekenstein-Hawking entropy in a certain limit. This proposal is applied to…
In this work, we derive the linearised equations of quadratic gravity from entanglement equilibrium of local causal diamonds. Rather than starting from the Wald entropy prescription (which depends on the gravitational Lagrangian), we employ…
We analyze the gravitational entropy defined by the Weyl curvature for the Hayward black hole, which is one of the regular black holes without singularity in the event horizon. Using the definition by the ratio of the Weyl curvature scalar…
We construct the most general theory of 2D Einstein-dilaton gravity coupled with $U(1)$ gauge fields that contains all the 2-derivative and the 4-derivative interactions allowed by the diffeomorphism invariance. We renormalise the 2D action…
We develop an approach to compute observables beyond the linear regime of dark matter perturbations for general dark energy and modified gravity models. We do so by combining the Effective Field Theory of Dark Energy and Effective Field…
We use the entropy function formalism introduced by A. Sen to obtain the entropy of $AdS_{2}\times S^{d-2}$ extremal and static black holes in four and five dimensions, with higher derivative terms of a general type. Starting from a…
It is very important to calculate the amount of radiation from a black hole as the radiation from a black hole contributes to its entropy. In this paper I have calculated the Entropy of a black hole from the action. I have used path…
Modifications of the area law are crucial in order to find agreement with microscopic entropy calculations based on string theory, when including contributions that are subleading for large charges. The deviations of the area law are in…
We consider an action for an abelian gauge field for which the density is given by a power of the Maxwell Lagrangian. In d spacetime dimensions this action is shown to enjoy the conformal invariance if the power is chosen as d/4. We take…
We prove that higher-dimension operators contribute positively to the entropy of a thermodynamically stable black hole at fixed mass and charge. Our results apply whenever the dominant corrections originate at tree level from quantum field…
I study the balance law equation of surface charges in the presence of background fields. The construction allows a unified description of Noether's theorem for both global and local symmetries. From the balance law associated with some of…
We show that for generic stationary spacetime and specific Killing fields, Wald's approach for quasi-local energy could be generalized to the first order formalism straightforwardly without introducing the Lorentz-Lie derivative. Via this…
We consider a general, classical theory of gravity with arbitrary matter fields in $n$ dimensions, arising from a diffeomorphism invariant Lagrangian, $\bL$. We first show that $\bL$ always can be written in a ``manifestly covariant" form.…
In this report, a general method to extract thermodynamic quantities from solutions of the Einstein equation is developed. In 1994, Wald established that the entropy of a black hole could be identified as a Noether charge associated with a…