Related papers: Can wormholes have negative temperatures?
Assuming that spacetime tunnels -wormholes and ringholes- naturally exist in the universe, we investigate the conditions making them embeddible in Friedmann space, and the possible observable effects of these tunnels, including: lensing and…
The Hawking temperature for the Schwarzschild black hole is divergent when the mass of the black hole vanishes; however the corresponding geometry becomes the Minkowski spacetime whose intrinsic temperature is zero. In connection with this…
We obtain a (5+1)-dimensional global flat embedding of the Gibbons-Maeda-Garfinkle-Horowitz-Strominger spacetime in Einstein frame, and a (5+2)-dimensional global flat embedding in string frame. We show that the local free-fall temperatures…
We find necessary and sufficient conditions for existence of a locally isometric embedding of a vacuum space-time into a conformally-flat 5-space. We explicitly construct such embeddings for any spherically symmetric Lorentzian metric in…
In this study, we reach the equations of motion of Morris-Thorne wormhole geometry by means of the Einstein Field Equations and Klein-Gordon Equation of Scalar-Tensor theory by direct calculation. We discuss the anisotropic matter energy…
The Hawking temperature for Schwarzschild black hole $T_H=1/8\pi M$ is singular in the limit of vanishing mass $M\to 0$. However, the Schwarzschild metric itself is regular in this limit, it is reduced to the Minkowski metric and there are…
Adopting the thin-layer improved brick-wall method, we investigate the thermodynamics of a black hole embedded in a spatially flat Friedmann-Robertson-Walker universe. We calculate the temperature and the entropy at every apparent horizon…
We study thermodynamic properties of Myers-Perry black holes by deriving explicit fundamental relations from which we can obtain the temperature and specific heat in terms of explicit control parameters in arbitrary dimensions. Using the…
We study the thermodynamic equilibrium of matter in a wormhole `station' which connects various distinct asymptotic regions of a spacetime. An example of the `station' is a traversable wormhole connecting two distant regions. The…
We tested the thermodynamic properties of charged BTZ-type black holes (BHs) in the framework of Bopp Podolsky electrodynamics, a higher derivative extension of Maxwells theory that preserves gauge invariance while introducing a massive…
In this letter, we obtain two new embedded WH solutions by using the class-I approach in the background of newly fourth-order Ricci inverse gravity. We show that the combination of these newly calculated shape functions and Ricci inverse…
We created a model of several dimensional physical universe. The extra dimensions associated with the four dimensional physical universe is assumed to have modified Gidding-Strominger wormhole core. This core is separated by a flexible…
Asymmetric thin-shell wormholes from two traversable Morris-Thorne wormhole spacetimes, with identical shape but different redshift functions, are constructed. Energy density of the thin-shell wormhole derives its power from a Morris-Thorne…
After a brief review of Goedel-type universes in string theory, we discuss some intriguing properties of black holes immersed in such backgrounds. Among these are the upper bound on the entropy that points towards a finite-dimensional…
Black holes are thermodynamic objects, but despite recent progress, the ultimate statistical mechanical origin of black hole temperature and entropy remains mysterious. Here I summarize an approach in which the entropy is viewed as arising…
Recent research shows that Hawking radiation (HR) is also possible around the trapping horizon of a wormhole. In this article, we show that the HR of gravitino (spin-$3/2$) particles from the traversable Lorentzian wormholes (TLWH) reveals…
It has been observed that for black holes in certain family of Horndeski gravity theories Wald's entropy formula does not lead to the correct first law for black hole thermodynamics. For this family of Horndeski theories speeds of…
The thermodynamic stability of a thin-shell wormhole in a Schwarzschild bulk is considered. From the first law, entropy function is found which satisfies the local intrinsic stability conditions. Heat capacity emerges as a well-defined…
We discuss the thermodynamic properties of the Friedmann-Robertson-Walker universe with dark energy fluids labelled by $\omega=p/\rho<-1/3$. Using the integrability condition, we show that the phantom phase of $w<-1$ can still be…
We investigate the temperature and energy on holographic screens for 4-dimensional black holes with the entropic force idea proposed by Verlinde. We find that the "Unruh-Verlinde temperature" is equal to the Hawking temperature on the…