Related papers: Infrared Effects and the Unruh State
It was recently advanced the argument that Unruh effect emerges from the study of quantum field theory in quantum space-time. Quantum space-time is identified with the Hilbert space of a new kind of quantum fields, the accelerated fields,…
We consider field quantization on an arbitrary null hypersurface in curved spacetime. We discuss the de Sitter horizon as the simplest example, relating the horizon quantization to the standard Fock space in the cosmological patch. We…
We compute the semiclassical current and stress-energy fluxes both at the event and Cauchy horizon of a near-extremal Reissner-Nordstr\"om black hole. We consider a minimally-coupled, massless, charged scalar field in the Unruh state,…
We study the Unruh effect for an observer with a finite lifetime, using the thermal time hypothesis. The thermal time hypothesis maintains that: (i) time is the physical quantity determined by the flow defined by a state over an observable…
We derive and study distorted, five-dimensional, electrically charged, non-extremal black holes on the example of a static and "axisymmetric" black hole distorted by external, electrically neutral matter.The solution satisfies…
We present a new method by which, in principle, it is possible to "see in absolute darkness," i.e., without exchanging any real quanta through quantum fields. This is possible because objects modify the mode structure of the vacuum in their…
In the context of the recently proposed type-II minimally modified gravity theory, i.e. a metric theory of gravity with two local physical degrees of freedom that does not possess an Einstein frame, we study spherically symmetric vacuum…
A recent calculation shows that the observed energy density in the Unruh state at the future event horizon as seen by a freely falling observer is finite if the observer is released from rest at any positive distance outside the horizon;…
In quantum field theory there exist states for which the energy density is negative. It is important that these negative energy densities satisfy constraints, such as quantum inequalities, to minimize possible violations of causality, the…
Quadratic scale-invariant gravity non minimally coupled to a scalar field provides a competitive model for inflation, characterized by the transition from an unstable to a stable fixed point, both characterized by constant scalar field…
The classical black hole spacetime is modified semiclassically, depending strongly on the choice of the quantum states. In particular, for the Boulware state the spacetime often takes a wormhole structure mimicking closely a spacetime with…
In this work, by a novel approach to studying the scattering of a Schwarzschild black hole, the non-commutativity is introduced as a perturbation. We begin by reformulating the Klein-Gordon equation for the scalar field in a new form that…
We study the stress energy two-point function to show how short distance correlations across the horizon transform into correlations among asymptotic states, for the Unruh effect, and for black hole radiation. In the first case the…
The aim of these notes is both to review the standard understanding of the Hawking effect, and to discuss the modifications to this understanding that might be required by new physics at short distances. The fundamentals of the Unruh effect…
When ground-state atoms are accelerated and the field with which they interact is in its normal vacuum state, the atoms detect Unruh radiation. We show that atoms falling into a black hole emit acceleration radiation which, under…
Black holes in Lorentz violating gravity enjoy a double horizon structure which resembles that of the Kerr solution in General Relativity. Moreover, when a scalar field with a modified dispersion relation is coupled to these backgrounds, an…
The boundary of any observer's spacetime is the boundary that divides what the observer can see from what they cannot see. The boundary of an observer's spacetime in the presence of a black hole is not the true (future event) horizon of the…
Black holes provide a natural laboratory to study particle physics and astrophysics. When black holes are surrounded by matter fields, there will be plenty of phenomena which can have observational consequences, from which we can learn…
We calculate the response functions of a freely falling Unruh detector in de Sitter space coupled to scalar fields of different coupling to the curvature, including the minimally coupled massless case. Although the responses differ strongly…
We discuss the problem of canonical quantization of a free real massive scalar field in the Schwarzschild spacetime. It is shown that a consistent procedure of canonical quantization of the field can be carried out without taking into…