199678166
Horizon entropy and higher curvature equations of state
The Clausius relation between entropy change and heat flux has previously been used to derive Einstein's field equations as an equation of state. We examine here whether a similar derivation can be given for extensions beyond Einstein gravity to include higher derivative and higher curvature terms.
118315517
Thermodynamic Route to Field Equations in Gravity
Spacetimes with horizons show a resemblance to thermodynamic systems and one can associate notions of temperature and entropy with them. Such notions provide us a possible alternative approach to understand the dynamics of gravity as an emergent phenomenon resulted out of thermodynamics of spacetime by interpreting the field equations as a thermodynamic identity TdS = dE+PdV. Interestingly, such equilibrium thermodynamic interpretation works only for Lanczos‐Lovelock theories. All these prelimany results point towards a deep connection among gravity, thermodynamics and quantum theory and also offer a new outlook regarding the nature of gravitational interaction.
28943117
Physical process first law and increase of horizon entropy for black holes in Einstein-Gauss-Bonnet gravity.
We establish the physical process version of the first law by studying small perturbations of a stationary black hole with a regular bifurcation surface in Einstein-Gauss-Bonnet gravity. Our result shows that when the stationary black hole is perturbed by a matter stress energy tensor and finally settles down to a new stationary state, the Wald entropy increases as long as the matter satisfies the null energy condition.
119290419
Hawking radiation as tunneling for spherically symmetric black holes: A generalized treatment
Abstract We present a derivation of Hawking radiation through tunneling mechanism for a general class of asymptotically flat, spherically symmetric spacetimes. The tunneling rate Γ ∼ exp ( Δ S ) arises as a consequence of the first law of thermodynamics, T d S = d E + P d V . Therefore, this approach demonstrates how tunneling is intimately connected with the first law of thermodynamics through the principle of conservation of energy. The analysis is also generally applicable to any reasonable theory of gravity so long as the first law of thermodynamics for horizons holds in the form, T d S = d E + P d V .
17880188
Phase transitions in higher derivative gravity and gauge theory: R-charged black holes
This is a continuation of our earlier work where we constructed a phenomenologically motivated effective action of the boundary gauge theory at finite temperature and finite gauge coupling on S3 × S1. In this paper, we argue that this effective action qualitatively reproduces the gauge theory representing various bulk phases of R-charged black hole with Gauss-Bonnet correction. We analyze the system both in canonical and grand canonical ensemble.
115620347
The Schwinger mechanisms in non-abelian gauge theories
Abstract An alternative to the Higgs-Kibble mechanism for the formulation of spontaneously broken gauge theories has been recently proposed. It is shown how the new procedures can be generalised to the case when non-Abelian gauge groups are present.
121294545
Gauge theories with strong coupling in four dimensions
Abstract The long distance behavior of singlet current correlation functions of gauge theories on a lattice are found approximately using the renormalization group. For strong coupling the behavior is similar to that found in the lattice massive Schwinger model.
117489045
Methods and Models for the Study of Decoherence
We shall review methods used in the description of decoherence on particle probes in experiments due to surrounding media. This will include conventional media as well as a model for space-time foam arising from non-critical string theory.
56462119
PT -Symmetric Interpretation of Double-Scaling
The conventional double-scaling limit of an O(N)-symmetric quartic quantum field theory is inconsistent because the critical coupling constant is negative. Thus, at the critical coupling the Lagrangian defines a quantum theory with an upside-down potential whose energy appears to be unbounded below. Worse yet, the integral representation of the partition function of the theory does not exist. It is shown that one can avoid these difficulties if one replaces the original theory by its PT-symmetric analog. For a zero-dimensional O(N)-symmetric quartic vector model the partition function of the PT-symmetric analog is calculated explicitly in the double-scaling limit.